Agonistic Binding Molecules to the Human OX40 Receptor

ABSTRACT

The present invention provides binding molecules, such as human binding molecules, that bind to and stimulate the human OX40-receptor. The invention also provides nucleic acids encoding such binding molecules. Methods for producing such binding molecules are also provided by the present invention. The binding molecules and nucleic acids are useful in the stimulation of human T-cells and can be used to enhance antigen-specific immune responses.

CROSS-REFERENCE TO RELATED APPLICATION

This is a national phase entry under 35 U.S.C. §371 of International Patent Application No. PCT/EP03/06341, filed Jun. 13, 2003, published in English as International Patent Publication No. WO 03/106498 on Dec. 24, 2003, which claims the benefit under 35 U.S.C. §119 of International Patent Application No. PCT/NL02/00389 filed Jun. 13, 2002.

FIELD OF THE INVENTION

The present invention relates generally to the field of biotechnology and more specifically to the field of medicine, more in particular, to agonistic binding molecules capable of specifically binding to the human OX40-receptor. The binding molecules are useful in immunotherapy.

BACKGROUND

The OX40-receptor (OX40R) (also known as CD134, ACT-4, ACT35) is a member of the TNF receptor family which is expressed on activated CD4+ T-cells (see WO 95/12673). Triggering of this receptor via the OX40-ligand, named OX40L, gp34 or ACT-4-ligand, present on activated B-cells and dendritic cells, enhances the proliferation of CD4+ T-cells during an immune response and influences the formation of CD4+ memory T-cells. Furthermore, the OX40R-OX40L system mediates adhesion of activated T-cells to endothelial cells, thus directing the activated CD4+ T-cells to the site of inflammation.

Inflammatory and autoimmune diseases, such as rheumatoid arthritis and inflammatory bowel disease, are characterized by an infiltration of activated T-cells at the site of inflammation, which is believed to orchestrate the response leading to chronic tissue destruction. In patients with inflammatory bowel disease, OX40+ CD4+ T-cells can be found in the gut associated with sites of inflammation. In addition, in patients suffering from acute graft-vs-host-disease, elevated levels of OX40+ peripheral CD4+ T-cells are present in peripheral blood. In rheumatoid arthritis patients, OX40+ CD4+ T-cells are present in synovial fluid, while they are virtually absent from peripheral blood. Furthermore, OX40+ CD4+ T-cells are found in inflamed synovial tissue in addition to cells expressing the ligand for the OX40-receptor. This is in contrast to patients suffering from osteoarthritis, a joint disease that is not mediated by inflammation, where both cell types could not be found in significant numbers.

Thus, in patients suffering from several inflammatory disorders elevated levels of OX40+ CD4+ T-cells are present at sites of inflammation, indicating that these cells may be involved in progression of autoimmune disease. A blockade of the OX40R-OX40L pathway using antibodies or fusion proteins has led to the attenuation of disease progression in several animal models of autoimmune disease.

Besides their presence in autoimmune diseases, it has been shown that OX40+ T-cells are present within tumor lesions containing tumor infiltrating lymphocytes and in tumor cell positive draining lymph nodes (Weinberg et al., 2000). It was shown in several tumor models in mice that engagement of the OX40-receptor in vivo during tumor priming significantly delayed and prevented the appearance of tumors as compared to control treated mice (Weinberg et al., 2000). Hence, it has been contemplated to enhance the immune response of a mammal to an antigen by engaging the OX40-receptor by administering an OX40-receptor binding agent (WO 99/42585; Weinberg et al., 2000). One possibility is to use a natural ligand of the OX40-receptor, i.e. the OX40-ligand, or fusion proteins thereof as an OX40-receptor binding ligand. Such proteins however have a fixed affinity for the receptor that is not easily changed, may not have the circulatory retention time to exert the desired therapeutic effect, and may give rise to immunogenicity (Weinberg et al., 2000).

Another possibility to stimulate T-cells by virtue of the OX40-receptor pathway, is to use antibodies against this receptor (Kaleeba et al., 1998; Weinberg et al., 2000). A rat anti-mouse OX40-receptor antibody named OX86 (Al-Shamkhani et al., 1996) appeared to engage the OX40-receptor in murine tumor models (Weinberg et al., 2000; U.S. Pat. No. 6,312,700).

To our knowledge agonistic antibodies, particularly human agonistic antibodies, that are capable of stimulating the human OX40-receptor have not been disclosed in the art. Furthermore, it is well known that non-human antibodies are limited in their use in vivo in humans. Problems associated with administration of non-human antibodies to humans are inter alia short serum half life, an inability to trigger certain human effector functions and elicitation of an unwanted dramatic immune response against the non-human antibody in a human.

In general, attempts to overcome the problems associated with use of fully non-human antibodies in humans, have involved genetically engineering the antibodies to be more “human-like”. A first stage in the humanization process was preparing chimeric antibodies, i.e. antibodies in which the variable regions of the antibody chains are derived from the non-human species and the constant regions of the antibody chains are human-derived. Subsequently, domains between the variable domains which specify the antigen binding were replaced by their human counterparts leading to so-called humanized antibodies. A disadvantage of these chimeric and humanized antibodies is that they still retain some non-human sequences and therefore still elicit an unwanted immune reaction, especially when administered for prolonged periods.

In the light of the above, there is still a need for human antibodies that stimulate the human OX40-receptor. These antibodies can be useful in inter alia the treatment and/or prevention of tumours in humans.

SUMMARY OF THE INVENTION

The invention provides agonistic binding molecules capable of specifically binding to the human OX40-receptor. In a preferred embodiment, said binding molecules are human binding molecules. Furthermore, the invention pertains to nucleic acid molecules encoding at least the binding region of the binding molecules. The invention further provides for the use of the binding molecules or nucleic acids for enhancing the immune response in a human, for use in the treatment of the human or animal body, and for the preparation of a medicament to treat a human having or at risk of developing a disorder or disease such as a neoplastic disorder or disease.

DESCRIPTION OF THE FIGURES

FIG. 1 shows the binding of anti-human OX40-receptor phage antibodies, that were selected using immobilized human OX40-Ig fusion protein, to human OX40-Ig fusion protein coated to ELISA plates. The Y-axis shows the absorbance at 492 nm.

FIG. 2 shows the binding of anti-human OX40-receptor phage antibodies, that were selected using immobilized human OX40-Ig fusion protein, to human OX40-receptor transfected PER.C6™ cells. In each picture the group of cells on the left are control transfected PER.C6™ cells and the group of cells on the right are OX40-receptor transfected PER.C6™ cells. The upper left picture shows binding of a control phage antibody directed against thyroglobulin.

In FIG. 3 the binding of anti-human OX40-receptor phage antibodies, selected using immobilized human OX40-Ig fusion protein, to OX40+ CD4+ T-cells is shown. In FIG. 3A the binding of the selected phage antibodies to a subset of CD4+ T-cells within tonsil mononuclear cells is shown. In FIG. 3B the binding of the phage antibodies to a subset of CD4+ T-cells within synovial fluid mononuclear cells is shown. In FIG. 3C the binding of the selected phage antibodies to peripheral blood CD4+ T-cells is displayed. The upper FACS plot in FIGS. 3A, 3B and 3C shows a control staining on CD4+ T cells using a PE-labelled mouse anti-human OX40 antibody.

FIG. 4 shows the binding of anti-human OX40-receptor phage antibodies, selected using OX40+ CD4+ T-cells, to OX40+ CD4+ T-cells (see FIG. 4A) and to human OX40-receptor transfected PER.C6™ cells (see FIG. 4B).

FIG. 5 shows the nucleotide sequence (SEQ ID NO:1) and amino acid sequence (SEQ ID NO:2) of the scFv called SC02008. The heavy chain CDR3 region is underlined.

FIG. 6 shows the nucleotide sequence (SEQ ID NO:3) and amino acid sequence (SEQ ID NO:4) of the scFv called SC02009. The heavy chain CDR3 region is underlined.

FIG. 7 shows the nucleotide sequence (SEQ ID NO:5) and amino acid sequence (SEQ ID NO:6) of the scFv called SC02010. The heavy chain CDR3 region is underlined.

FIG. 8 shows the nucleotide sequence (SEQ ID NO:7) and amino acid sequence (SEQ ID NO:8) of the scFv called SC02011. The heavy chain CDR3 region is underlined.

FIG. 9 shows the nucleotide sequence (SEQ ID NO:9) and amino acid sequence (SEQ ID NO:10) of the scFv called SC02012. The heavy chain CDR3 region is underlined.

FIG. 10 shows the nucleotide sequence (SEQ ID NO:11) and amino acid sequence (SEQ ID NO:12) of the scFv called SC02021. The heavy chain CDR3 region is underlined.

FIG. 11 shows the nucleotide sequence (SEQ ID NO:13) and amino acid sequence (SEQ ID NO:14) of the scFv called SC02022. The heavy chain CDR3 region is underlined.

FIG. 12 shows the nucleotide sequence (SEQ ID NO:15) and amino acid sequence (SEQ ID NO:16) of the scFv called SC02023. The heavy chain CDR3 region is underlined.

FIG. 13 shows the construction of the bivalent scFv expression vector pPICZbiFVH. In FIG. 13A the vector pPICZαB is shown and in FIG. 13B the bivalent scFv expression vector pPicZbiFVH is shown. FIG. 13C shows the cloning strategy of scFv's into pPicZbiFVH.

FIG. 14 shows the functional activity of the anti-human OX40-receptor bivalent scFv's SC02008 and SC02023 in an in vitro T-cell costimulation assay. FIG. 14A shows the stimulation assay for the bivalent scFv SC02008 and FIG. 14B shows the stimulation assay for the bivalent scFv SC02023.

FIG. 15 shows the binding of human IgG molecules called 008, 011, 021 and 023 to human OX40-receptor transfected PER.C6™ cells.

DETAILED DESCRIPTION OF THE INVENTION

Herebelow follow definitions of terms as used in the invention

Definitions

Agonistic Binding Molecule

The term “agonistic binding molecule” as used herein in general refers to a binding molecule which, when combined with a receptor, e.g. the OX40-receptor, on a cell, is capable of binding to the receptor and is capable of initiating/mimicking/stimulating a reaction or activity that is similar to or the same as that initiated/mimicked/stimulated by the receptor's natural ligand, e.g. the OX40-ligand. An agonistic binding molecule of the OX40-receptor is capable of immunospecifically binding to the OX40-receptor expressed by activated CD4+ T-cells, and is capable of inducing/augmenting/enhancing/stimulating the activation of a signal transduction pathway associated with the OX40-receptor such as for instance the activation of the activated CD4+ T-cells.

Agonistic binding molecules are capable of inducing/augmenting/enhancing/stimulating any or all of, but not limited to, the following responses: proliferation of CD4+ T-cells during an immune response, stimulation of cytokine production, proliferation of Th1 or Th2 effector cells, development of a Th2 response, generation of CD4+ memory T cells. An agonistic binding molecule may induce/enhance/stimulate/augment any one or more of the responses by 5%, 10%, 15%, 20%, 25%, 30%, 35%, preferably 40%, 45%, 50%, 55%, 60%, more preferably 70%, 80%, 85%, and most preferably 90%, 95%, 99%, or 100%. In particular, an agonistic binding molecule that is capable of inducing/enhancing/stimulating/augmenting an activated CD4+ T-cell activates an activated CD4+ T-cell 1-5 fold, 5-10 fold, 10-20 fold, or more than 20 fold as compared to the ability of the agonistic binding molecule to activate a resting T-cell, i.e. T-cells which do not express or express low to undetectable levels of the T-cell activation marker CD4. Methods for determining the activation/stimulation/induction/enhancement are known in the art and include, but are not limited to, antigen specific proliferation assays, cytokine ELISA assays, elispot assays, detection of antigen specific T-cells using flow cytometry methods employing Major Histocompatibility Complex (MHC) peptide tetramers. The agonistic binding molecules are preferably against epitopes within the extracellular domain of the OX40-receptor. The term “agonistic binding molecule” as used herein covers inter alia agonistic human anti-OX40-receptor monoclonal antibodies or parts thereof and agonistic human anti-OX40-receptor compositions with polyepitopic specificity.

Amino Acid Sequence

The term “amino acid sequence” as used herein refers to naturally occuring or synthetic molecules and to a peptide, oligopeptide, polypeptide or protein sequence.

Binding Molecule

As used herein the term “binding molecule” refers to an intact immunoglobulin including monoclonal antibodies, such as chimeric, humanized or human monoclonal antibodies, or to an antigen-binding and/or variable domain comprising fragment of an immunoglobulin that competes with the intact immunoglobulin for specific binding to the binding partner of the immunoglobulin, e.g. OX40-receptor. Regardless of structure, the antigen-binding fragment binds with the same antigen that is recognized by the intact immunoglobulin. An antigen-binding fragment can comprise a peptide or polypeptide comprising an amino acid sequence of at least 2 contiguous amino acid residues, at least 5 contiguous amino acid residues, at least 10 contiguous amino acid residues, at least 15 contiguous amino acid residues, at least 20 contiguous amino acid residues, at least 25 contiguous amino acid residues, at least 30 contiguous amino acid residues, at least 35 contiguous amino acid residues, at least 40 contiguous amino acid residues, at least 50 contiguous amino acid residues, at least 60 contiguous amino residues, at least 70 contiguous amino acid residues, at least contiguous 80 amino acid residues, at least contiguous 90 amino acid residues, at least contiguous 100 amino acid residues, at least contiguous 125 amino acid residues, at least 150 contiguous amino acid residues, at least contiguous 175 amino acid residues, at least 200 contiguous amino acid residues, or at least contiguous 250 amino acid residues of the amino acid sequence of the binding molecule.

The term “binding molecule”, as used herein also includes the immunoglobulin classes and subclasses known in the art. Depending on the amino acid sequence of the constant domain of their heavy chains, binding molecules can be divided into the five major classes of intact antibodies: IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses (isotypes), e.g., IgA1, IgA2, IgG1, IgG2, IgG3 and IgG4.

Antigen-binding fragments include, inter alia, Fab, F(ab′), F(ab′)2, Fv, dAb, Fd, complementarity determining region (CDR) fragments, single-chain antibodies (scFv), bivalent single-chain antibodies, diabodies, triabodies, tetrabodies, (poly)peptides that contain at least a fragment of an immunoglobulin that is sufficient to confer specific antigen binding to the (poly)peptide, etc. The above fragments may be produced synthetically or by enzymatic or chemical cleavage of intact immunoglobulins or they may be genetically engineerd by recombinant DNA techniques. The methods of production are well known in the art and are described, for example, in Antibodies: A Laboratory Manual, Edited by: E. Harlow and D, Lane (1988), Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., which is incorporated herein by reference. A binding molecule or antigen-binding fragment thereof may have one or more binding sites. If there is more than one binding site, the binding sites may be identical to one another or they may be different.

The binding molecule can be a naked or unconjugated binding molecule. A naked or unconjugated binding molecule is intended to refer to a binding molecule that is not conjugated, operatively linked or otherwise physically or functionally associated with an effector moiety or tag, such as inter alia a toxic substance, a radioactive substance, a liposome, or an enzyme. It will be understood that naked or unconjugated binding molecules do not exclude binding molecules that have been stabilized, multimerized, humanized or in any other way manipulated, other than by the attachment of an effector moiety or tag. Accordingly, all posttranslationally modified naked and unconjugated binding molecules are included herewith, including where the modifications are made in the natural binding molecule-producing cell environment, by a recombinant binding molecule-producing cell, and are introduced by the hand of man after initial binding molecule preparation. Of course, the term naked or unconjugated binding molecule does not exclude the ability of the binding molecule to form functional associations with effector cells and/or molecules after administration to the body, as some of such interactions are necessary in order to exert a biological effect. The lack of associated effector group or tag is therefore applied in definition to the naked or unconjugated binding molecule in vitro, not in vivo.

Complementary Determining Regions (CDR)

The term “complementary determining regions” as used herein means sequences within the variable regions of binding molecules, such as immunoglobulins, that generate the antigen binding site which is complementary in shape and charge distribution to the epitope recognized on the antigen. The CDR regions can be specific for linear epitopes, discontinuous epitopes, or conformational epitopes of proteins or protein fragments, either as present on the protein in its native conformation or, in some cases, as present on the proteins as denatured, e.g., by solubilization in SDS. Epitopes may also consist of posttranslational modifications of proteins.

Deletion

The term “deletion”, as used herein, denotes a change in either amino acid or nucleotide sequence in which one or more amino acid or nucleotide residues, respectively, are absent as compared to the parent, often the naturally occurring, molecule.

Expression-Regulating Nucleic Acid Sequence

The term “expression-regulating nucleic acid sequence” as used herein refers to polynucleotide sequences necessary for and/or affecting the expression of an operably linked coding sequence in a particular host organism. Generally, when two nucleic acid sequences are operably linked, they will be in the same orientation and usually also in the same reading frame. They usually will be essentially contiguous, although this may not be required. The expression-regulating nucleic acid sequences, such as inter alia appropriate transcription initiation, termination, promoter, enhancer sequences; repressor or activator sequences; efficient RNA processing signals such as splicing and polyadenylation signals; sequences that stabilize cytoplasmic mRNA; sequences that enhance translation efficiency (e.g., ribosome binding sites); sequences that enhance protein stability; and when desired, sequences that enhance protein secretion, can be any nucleic acid sequence showing activity in the host organism of choice and can be derived from genes encoding proteins, which are either homologous or heterologous to the host organism.

Functional Variant

The term “functional variant”, as used herein, refers to a binding molecule that comprises a nucleotide and/or amino acid sequence that is altered by one or more nucleotides and/or amino acids compared to the nucleotide and/or amino acid sequences of the parent binding molecule and that is still capable of competing for binding to the binding partner, e.g. OX40-receptor, with the parent binding molecule. In other words, the modifications in the amino acid and/or nucleotide sequence of the parent binding molecule do not significantly affect or alter the binding characteristics of the binding molecule encoded by the nucleotide sequence or containing the amino acid sequence, i.e. the binding molecule is still able to recognize and bind its target. The functional variant may have conservative sequence modifications including nucleotide and amino acid substitutions, additions and deletions. These modifications can be introduced by standard techniques known in the art, such as site-directed mutagenesis and random PCR-mediated mutagenesis, and may comprise natural as well as non-natural nucleotides and amino acids.

Conservative amino acid substitutions include the ones in which the amino acid residue is replaced with an amino acid residue having similar structural or chemical properties. Families of amino acid residues having similar side chains have been defined in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cystine, tryptophan), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Furthermore, a variant may have non-conservative amino acid substitutions, e.g., replacement of an amino acid with an amino acid residue having different structural or chemical properties. Similar minor variations may also include amino acid deletions or insertions, or both. Guidance in determining which amino acid residues may be substituted, inserted, or deleted without abolishing immunological activity may be found using computer programs well known in the art.

A mutation in a nucleotide sequence can be a single alteration made at a locus (a point mutation), such as transition or transversion mutations, or alternatively, multiple nucleotides may be inserted, deleted or changed at a single locus. In addition, one or more alterations may be made at any number of loci within a nucleotide sequence. The mutations may be performed by any suitable method known in the art.

Host

The term “host”, as used herein, is intended to refer to an organism or a cell into which a vector such as a cloning vector or an expression vector has been introduced. The organism or cell can be prokaryotic or eukaryotic. It should be understood that this term is intended to refer not only to the particular subject organism or cell, but to the progeny of such an organism or cell as well. Because certain modifications may occur in succeeding generations due to either mutation or environmental influences, such progeny may not, in fact, be identical to the parent organism or cell, but are still included within the scope of the term “host” as used herein.

Human

The term “human”, when applied to binding molecules as defined herein, refers to molecules that are either directly derived from a human or based upon a human sequence. When a binding molecule is derived from or based on a human sequence and subsequently modified, it is still to be considered human as used throughout the specification. In other words, the term human, when applied to binding molecules is intended to include binding molecules having variable and constant regions derived from human germline immunoglobulin sequences based on variable or constant regions either or not occuring in a human or human lymphocyte or in modified form. Thus, the human binding molecules may include amino acid residues not encoded by human germline immunoglobulin sequences, comprise substitutions and/or deletions (e.g., mutations introduced by for instance random or site-specific mutagenesis in vitro or by somatic mutation in vivo). “Based on” as used herein refers to the situation that a nucleic acid sequence may be exactly copied from a template, or with minor mutations, such as by error-prone PCR methods, or synthetically made matching the template exactly or with minor modifications. Semisynthetic molecules based on human sequences are also considered to be human as used herein.

Immune Response

The term “immune response” as used herein refers to an antagonistic and specific host reaction in response to foreign or self antigens, involving the formation of antibodies by B-cells or a cell-mediated response by T-cells.

Insertion

The term “insertion”, also known as the term “addition”, denotes a change in an amino acid or nucleotide sequence resulting in the addition of one or more amino acid or nucleotide residues, respectively, as compared to the parent, often the naturally occurring, molecule.

Internalizing Binding Molecule

The term “internalizing binding molecule” as used herein means a binding molecule as defined herein that is capable of being internalized within the target cells to which it binds. In other words, the binding molecule is taken up, i.e. transported from the outside (cell surface) of a target cell to the inside, e.g. into the endosomal compartment or other compartment or into the cytoplasm of the cell, by the target cells upon binding to the binding partner of the binding molecule.

Isolated

The term “isolated”, when applied to binding molecules as defined herein, refers to binding molecules that are substantially free of other proteins or polypeptides, particularly free of other binding molecules having different antigenic specificities, and are also substantially free of other cellular or tissue material and/or chemical precursors or other chemicals. For example, when the binding molecules are recombinantly produced, they are preferably substantially free of culture medium, and when the binding molecules are produced by chemical synthesis, they are preferably substantially free of chemical precursors or other chemicals, i.e., they are separated from chemical precursors or other chemicals which are involved in the synthesis of the protein. Preferably, substantially free means that the binding molecule will typically comprise about 50%, 60%, 70%, 80% or 90% W/W of a sample, more usually about 95%, and preferably will be over 99% pure.

The term “isolated” when applied to nucleic acid molecules encoding binding molecules as defined herein, is intended to refer to nucleic acid molecules in which the nucleotide sequences encoding the binding molecules are free of other nucleotide sequences, particularly nucleotide sequences encoding binding molecules that bind binding partners other than the OX40-receptor. Furthermore, the term “isolated” refers to nucleic acid molecules that are substantially separated from other cellular components that naturally accompany the native nucleic acid molecule in its natural host, e.g., ribosomes, polymerases, or genomic sequences with which it is naturally associated. Moreover, “isolated” nucleic acid molecules, such as a cDNA molecules, can be substantially free of other cellular material, or culture medium when produced by recombinant techniques, or substantially free of chemical precursors or other chemicals when chemically synthesized.

Monoclonal Antibody

The term “monoclonal antibody” as used herein refers to a preparation of antibody molecules of single molecular composition. A monoclonal antibody displays a single binding specificity and affinity for a particular epitope. Accordingly, the term “human monoclonal antibody” refers to an antibody displaying a single binding specificity which have variable and constant regions derived from or based on human germline immunoglobulin sequences or derived from completely synthetic sequences.

Naturally Occuring

The term “naturally-occurring” as used herein as applied to an object refers to the fact that an object can be found in nature. For example, a polypeptide or polynucleotide sequence that is present in an organism that can be isolated from a source in nature and which has not been intentionally modified by man in the laboratory is naturally-occurring.

Neoplastic Cells

The term “neoplastic cells” as used herein refers to cells that result from abnormal autonomous new growth which has no apparent physiological function. A neoplastic cell further includes transformed cells and cancer cells including blood cancers (benign and malignant).

Nucleic Acid Molecule

The term “nucleic acid molecule” as used in the present invention refers to a polymeric form of nucleotides and includes both sense and antisense strands of RNA, cDNA, genomic DNA, and synthetic forms and mixed polymers of the above. A nucleotide refers to a ribonucleotide, deoxynucleotide or a modified form of either type of nucleotide. The term also includes single- and double-stranded forms of DNA. In addition, a polynucleotide may include either or both naturally-occurring and modified nucleotides linked together by naturally-occurring and/or non-naturally occurring nucleotide linkages. The nucleic acid molecules may be modified chemically or biochemically or may contain non-natural or derivatized nucleotide bases, as will be readily appreciated by those of skill in the art. Such modifications include, for example, labels, methylation, substitution of one or more of the naturally occurring nucleotides with an analog, internucleotide modifications such as uncharged linkages (e.g., methyl phosphonates, phosphotriesters, phosphoramidates, carbamates, etc.), charged linkages (e.g., phosphorothioates, phosphorodithioates, etc.), pendent moieties (e.g., polypeptides), intercalators (e.g., acridine, psoralen, etc.), chelators, alkylators, and modified linkages (e.g., alpha anomeric nucleic acids, etc.). The above term is also intended to include any topological conformation, including single-stranded, double-stranded, partially duplexed, triplex, hairpinned, circular and padlocked conformations. Also included are synthetic molecules that mimic polynucleotides in their ability to bind to a designated sequence via hydrogen bonding and other chemical interactions. Such molecules are known in the art and include, for example, those in which peptide linkages substitute for phosphate linkages in the backbone of the molecule. A reference to a nucleic acid sequence encompasses its complement unless otherwise specified. Thus, a reference to a nucleic acid molecule having a particular sequence should be understood to encompass its complementary strand, with its complementary sequence. The complementary strand is also useful, e.g., for antisense therapy, hybridization probes and PCR primers.

Operably Linked

The term “operably linked” refers to two or more nucleic acid sequence elements that are physically linked and are in a functional relationship with each other. For instance, a promoter is operably linked to a coding sequence if the promoter is able to initiate or regulate the transcription or expression of a coding sequence, in which case the coding sequence should be understood as being “under the control of” the promoter. Generally, when two nucleic acid sequences are operably linked, they will be in the same orientation and usually also in the same reading frame. They usually will be essentially contiguous, although this may not be required.

Pharmaceutically Acceptable Excipient

By “pharmaceutically acceptable excipient” is meant any inert substance that is combined with an active molecule such as a drug, agent, or binding molecule for preparing an agreeable or convenient dosage form. The “pharmaceutically acceptable excipient” is an excipient that is non-toxic to recipients at the dosages and concentrations employed and is compatible with other ingredients of the formulation comprising the drug, agent or binding molecule.

Specifically Binding

The term “specifically binding”, as used herein, in reference to the interaction of a binding molecule, e.g. an antibody, and its binding partner, e.g. an antigen, means that the interaction is dependent upon the presence of a particular structure, e.g. an antigenic determinant or epitope, on the binding partner. In other words, the antibody preferentially binds or recognizes the binding partner even when the binding partner is present in a mixture of other molecules. The binding may be mediated by covalent or non-covalent interactions or a combination of both. In yet other words, the term “specifically binding” means immunospecifically binding to an antigen or a fragment thereof and not immunospecifically binding to other antigens. A binding molecule that immunospecifically binds to an antigen may bind to other peptides or polypeptides with lower affinity as determined by, e.g., radioimmunoassays (RIA), enzyme-linked immunosorbent assays (ELISA), BIAcore, or other assays known in the art. Binding molecules or fragments thereof that immunospecifically bind to an antigen may be cross-reactive with related antigens. Preferably, binding molecules or fragments thereof that immunospecifically bind to an antigen do not cross-react with other antigens.

Substitutions

A “substitution”, as used herein, denotes the replacement of one or more amino acids or nucleotides by different amino acids or nucleotides, respectively.

Therapeutically Effective Amount

The term “therapeutically effective amount” refers to an amount of the binding molecule as defined herein that is effective for preventing, ameliorating or treating a disorder or disease wherein the OX40-receptor molecules play a role or are associated with.

Treatment

The term “treatment” refers to therapeutic treatment as well as prophylactic or preventative measures to cure or halt or at least retard disease progress. Those in need of treatment include those already inflicted with a disease or disorder wherein OX40-receptor molecules play a role or are associated with as well as those in which the disease or disorder is to be prevented. Prevention encompasses inhibiting or reducing the spread of the disease or disorder or inhibiting or reducing the onset, development or progression of one or more of the symptoms associated with the disease or disorder wherein OX40-receptor molecules play a role or are associated with.

Vector

The term “vector” denotes a nucleic acid molecule into which a second nucleic acid molecule can be inserted for introduction into a host where it will be replicated, and in some cases expressed. In other words, a vector is capable of transporting a nucleic acid molecule to which it has been linked. Cloning as well as expression vectors are contemplated by the term “vector”, as used herein. Vectors include, but are not limited to, plasmids, cosmids, bacterial artificial chromosomes (BAC) and yeast artificial chromosomes (YAC) and vectors derived from bacteriophages or plant or animal (including human) viruses. Vectors comprise an origin of replication recognized by the proposed host and in case of expression vectors, promoter and other regulatory regions recognized by the host. A vector containing a second nucleic acid molecule is introduced into a cell by transformation, transfection, or by making use of viral entry mechanisms. Certain vectors are capable of autonomous replication in a host into which they are introduced (e.g., bacterial vectors having a bacterial origin of replication). Other vectors can be integrated into the genome of a host upon introduction into the host, and thereby are replicated along with the host genome.

In a first aspect, the present invention provides agonistic binding molecules, capable of binding, preferably specifically binding, to or capable of associating with the human OX40-receptor. The agonistic binding molecules are also capable of binding, particularly specifically binding, to a fragment of the human OX40-receptor, the fragment at least comprising an antigenic determinant of the human OX40-receptor that is recognized by at least one of the agonistic binding molecules of the invention. The human OX40-receptor is selectively expressed by activated immune cells, such as activated CD4+ T-cells. The binding molecules of the invention are capable of stimulating and/or activating and/or enhancing and/or augmenting and/or inducing activated CD4+ T-cells. The expression of CD4 on activated T-cells can be measured by methods known in the art, including, but not limited to, FACS analysis, immunofluorescence assays, RT-PCR, Northern blot analysis and Western blot analysis.

In a preferred embodiment, the agonistic binding molecules according to the invention are human agonistic binding molecules. Preferably, the human binding molecules are derived from a semisynthetic library based on human sequences and mutated using error-prone PCR to increase specificities. A human binding molecule according to the invention such as an antibody lacks murine-derived sequences, in contrast to mouse antibodies obtained by hybridoma technology (Kohler and Milstein, 1975), or variants thereof such as chimeric antibodies or humanized antibodies. Human antibodies have the advantage that when administered to humans an anti-antibody immunogenic response will be extremely low or absent, whereas the murine derived antibodies can give rise to such responses quite extensively (Van Kroonenburgh and Pauwels, 1988). A binding molecule is for instance based upon a human sequence when it has been obtained from a library of human binding molecules. Such a library may also comprise human binding molecules that are based upon a human sequence but containing mutations, e.g. a semi-synthetic library, as was used to obtain molecules according to the present invention. ‘Based upon’ as used herein, is meant to include the synthetic construction of genetic information based upon knowledge of such genetic information. Such methods include the use of human or human derived genetic material as a template for PCR to construct a new binding molecule encoding construct that is based upon the sequence of the template, the construction of completely synthetic genetic information with a desired sequence e.g. by linking synthetic oligonucleotides to a desired construct, and the like. It is to be understood that ‘based upon’ does not exclusively mean a direct cloning of the wild type DNA. A person skilled in the art will also be aware of the possibilities of molecular biology to obtain mutant forms of a certain piece of nucleic acid.

The agonistic binding molecules of the invention can be intact immunoglobulin molecules such as polyclonal or monoclonal antibodies, in particular human monoclonal antibodies, or the binding molecules can be antigen-binding fragments including, but not limited to, Fab, F(ab′), F(ab′)2, Fv, dAb, Fd, complementarity determining region (CDR) fragments, single-chain antibodies (scFv), bivalent single-chain antibodies, diabodies, triabodies, tetrabodies, and (poly)peptides that contain at least a fragment of an immunoglobulin that is sufficient to confer specific antigen binding to the (poly)peptides. The agonistic binding molecules of the invention can be used in non-isolated or isolated form. Furthermore, the agonistic binding molecules of the invention can be used alone or in a mixture/composition comprising at least one agonistic binding molecule (or variant or fragment thereof) of the invention. The mixture/composition may further comprise at least one other therapeutic agent. In one embodiment, the therapeutic agent can be a natural ligand of the OX40-receptor or a variant of the natural ligand still capable of binding to the human OX40-receptor. The agonistic binding molecules of the invention can act synergistically in vitro with the natural ligand, e.g. OX40-ligand. An advantage of agonistic binding molecules acting synergistically with the natural ligand could be that they may enhance the effect of OX40-ligand present in vivo, rather than only substituting it. Such synergistic activity can be determined by a functional assays known to the skilled artisan.

Typically, agonistic binding molecules according to the invention can bind to their binding partners, i.e. the human OX40-receptor, with an affinity constant (Kd-value) that is lower than 0.2×10⁻⁴ M, 1.0×10⁻⁵ M, 1.0×10⁻⁶ M, 1.0×10⁻⁶ M, preferably lower than 1.0×10⁻⁸ M, more preferably lower than 1.0×10⁻⁹ M, more preferably lower than 1.0×10⁻¹⁰ M, even more preferably lower than 1.0×10⁻¹¹ M, and in particular lower than 1.0×10⁻¹² M. The affinity constants can vary for antibody isotypes. For example, affinity binding for an IgM isotype refers to a binding affinity of at least about 1.0×10⁻⁷ M. Affinity constants can be measured using surface plasmon resonance, i.e. an optical phenomenon that allows for the analysis of real-time biospecific interactions by detection of alterations in protein concentrations within a biosensor matrix, for example using the BIAcore system (Pharmacia Biosensor AB, Uppsala, Sweden).

The agonistic binding molecule of the invention may internalize upon binding to the human OX40-receptor. Furthermore, the agonistic binding molecules according to the invention may bind to the human OX40-receptor in soluble form or may bind to the human OX40-receptor bound or attached to a carrier or substrate, e.g., microtiter plates, membranes and beads, etc. Carriers or substrates may be made of glass, plastic (e.g., polystyrene), polysaccharides, nylon, nitrocellulose, or teflon, etc. The surface of such supports may be solid or porous and of any convenient shape. Furthermore, the agonistic binding molecules may bind to the human OX40-receptor in purified or non-purified form. Preferably, the agonistic binding molecules are capable of specifically binding to the human OX40-receptor associated with cells, such as activated CD4+ T-cells or portions or parts of these cells comprising the human OX40-receptor or a fragment thereof.

In another embodiment, the binding molecules of the invention comprises at least a CDR3 region comprising the amino acid sequence selected from the group consisting of SEQ ID NO:17 (DRYSQVHYALDY), SEQ ID NO:18 (DRYVNTSNAFDY), SEQ ID NO:19 (DMSGFHEFDY), SEQ ID NO:20 (DRYFRQQNAFDY), SEQ ID NO:21 (ARAAGTIFDY), SEQ ID NO:22 (DRYITLPNALDY), SEQ ID NO:23 (YDEPLTIYWFDS) and SEQ ID NO:24 (YDNVMGLYWFDY).

In yet another aspect, the invention provides binding molecules of the invention comprising a heavy chain comprising the amino acid sequence selected from the group consisting of SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27 and SEQ ID NO:28. In a further embodiment the invention pertains to binding molecules comprising a heavy chain comprising the amino acid sequence of SEQ ID NO:25 and a light chain comprising the amino acid sequence of SEQ ID NO:29, a heavy chain comprising the amino acid sequence of SEQ ID NO:26 and a light chain comprising the amino acid sequence of SEQ ID NO:30, a heavy chain comprising the amino acid sequence of SEQ ID NO:27 and a light chain comprising the amino acid sequence of SEQ ID NO:31 or a heavy chain comprising the amino acid sequence of SEQ ID NO:28 and a light chain comprising the amino acid sequence of SEQ ID NO:32.

Another aspect of the invention includes functional variants of agonistic binding molecules or fragments thereof as defined herein. Molecules are functional variants of a binding molecule, when the variants are capable of competing for specifically binding to the human OX40-receptor, preferably competing for the same binding site on the human OX40-receptor, with the parent binding molecules. In other words, when the functional variants are still capable of immunospecifically binding to the human OX40-receptor or a portion thereof. Furthermore, the functional variants must be capable of inducing/stimulating/enhancing/augmenting activated CD4+ T-cells. In other words, the functional variants must also have agonistic activity. This agonistic activity can be higher or lower than the agonistic activity of the parent binding molecules of the invention. Functional variants include, but are not limited to, derivatives that are substantially similar in primary structural sequence, but which contain e.g. in vitro or in vivo modifications, chemical and/or biochemical, that are not found in the parent binding molecule. Such modifications include inter alia acetylation, acylation, ADP-ribosylation, amidation, covalent attachment of flavin, covalent attachment of a heme moiety, covalent attachment of a nucleotide or nucleotide derivative, covalent attachment of a lipid or lipid derivative, covalent attachment of phosphatidylinositol, cross-linking, cyclization, disulfide bond formation, demethylation, formation of covalent cross-links, formation of cystine, formation of pyroglutamate, formylation, gamma-carboxylation, glycosylation, GPI-anchor formation, hydroxylation, iodination, methylation, myristoylation, oxidation, pegylation, proteolytic processing, phosphorylation, prenylation, racemization, selenoylation, sulfation, transfer-RNA mediated addition of amino acids to proteins such as arginylation, and ubiquitination.

Alternatively, functional variants can be binding molecules as defined in the present invention comprising an amino acid sequence containing substitutions, insertions, deletions or combinations thereof of one or more amino acids compared to the amino acid sequences of the parent binding molecules. Furthermore, functional variants can comprise truncations of the amino acid sequence at either or both the amino or carboxy termini. Functional variants according to the invention may have the same or different, either higher or lower, binding affinities compared to the parent binding molecule but are still capable of binding to the human OX40-receptor present on e.g. a CD4+ T-cell. For instance, functional variants according to the invention may have increased or decreased binding affinities for the human OX40-receptor compared to the parent binding molecules. Preferably, the amino acid sequences of the variable regions, including, but not limited to, framework regions, hypervariable regions, in particular the CDR3 regions, are modified. Generally, the light chain and the heavy chain variable regions comprise three hypervariable regions, comprising three CDRs, and more conserved regions, the so-called framework regions (FRs). The hypervariable regions comprise amino acid residues from CDRs and amino acid residues from hypervariable loops. Functional variants intended to fall within the scope of the present invention have at least 50%, preferably at least 60%, at least 70%, at least 75%, more preferably at least 80%, at least 85%, even more preferably at least 90%, at least 95%, and in particluar at least 97%, at least 98%, at least 99% amino acid sequence homology with the parent binding molecules as defined herein. Computer algorithms such as inter alia Gap or Bestfit known to a person skilled in the art can be used to optimally align amino acid sequences to be compared and to define similar or identical amino acid residues.

Functional variants of the invention can be obtained by altering the nucleotide sequence of parent binding molecules or parts thereof by general molecular biology methods known in the art including, but not limited to, error-prone PCR, oligonucleotide-directed mutagenesis and site-directed mutagenesis. Mutations in the nucleotide sequences may render a different functionality, but they may also be silent in a way that certain mutations do not alter the functionality of that particular piece of DNA and its encoded protein. A person skilled in the art will appreciate the fact that certain deletions, swaps, (point)mutations, additions, substitutions etc. may still result in a nucleic acid that has a similar function as the original nucleic acid. It is therefore to be understood that such alterations that do not significantly alter the functionality of the encoded agonistic binding molecules against the human OX40-receptor are within the scope of the present invention. Human antibodies according to the invention may therefore also contain (semi-)synthetic regions, e.g. in the CDR regions. It is for instance possible to alter the CDR regions of the variable domains of binding molecules by site-directed mutagenesis, oligo-directed mutagenesis, error-prone PCR, cloning of restriction fragments, and the like.

In yet a further aspect, the invention includes immunoconjugates, i.e. molecules comprising at least one agonistic binding molecule as defined herein and further comprising at least one tag, such as a therapeutic moiety. Also contemplated in the present invention are mixtures of immunoconjugates according to the invention or mixtures of at least one immunoconjugates according to the invention and another molecule, such as a therapeutic agent or another binding molecule. In an embodiment, the immunoconjugates of the invention comprise more than one tag. These tags can be the same or distinct from each other and can be joined/conjugated non-covalently to the binding molecules. The tags can be joined/conjugated directly to the binding molecules through covalent bonding, including, but not limited to, disulfide bonding, hydrogen bonding, electrostatic bonding, recombinant fusion and conformational bonding. Alternatively, the tags can be joined/conjugated to the binding molecules by means of one or more linking compounds. Techniques for conjugating tags to binding molecules, are well known, see, e.g., Arnon et al., Monoclonal Antibodies For Immunotargeting Of Drugs In Cancer Therapy, p. 243-256 in Monoclonal Antibodies And Cancer Therapy (1985), Edited by: Reisfeld et al., A. R. Liss, Inc.; Hellstrom et al., Antibodies For Drug Delivery, p. 623-653 in Controlled Drug Delivery, 2^(nd) edition (1987), Edited by: Robinson et al., Marcel Dekker, Inc.; Thorpe, Antibody Carriers Of Cytotoxic Agents, p. 475-506 In Cancer Therapy: A Review, in Monoclonal Antibodies' 84 : Biological And Clinical Applications (1985), Edited by: Pinchera et al.; Analysis, Results, And Future Prospective Of The Therapeutic Use Of Radiolabeled Antibody In Cancer Therapy, p. 303-316 in Monoclonal Antibodies For Cancer Detection And Therapy (1985), Edited by: Baldwin et al., Academic Press.

In a specific embodiment, the tags comprise a compound that further enhances the immune response, such as a compound that stimulates and/or activates and/or enhances and/or augments and/or induces activated immune cells, e.g. activated T-cells such as activated CD4+ T-cells. Such compounds may include, but are not limited to, binding molecules, small molecules, organic or inorganic compounds, enzymes, polynucleotide sequences, plasmids, proteins, peptides, liposomes or combinations thereof. Examples of compounds capable of enhancing the immune response include, but are not limited to, compounds that activate a cytokine receptor such as inter alia cytokines including, but not limited to, CSF-1, Flt3 ligand, G-CSF, GM-CSF, IFN-α, IFN-β, IFN-γ, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-15, IL-18, M-CSF, and TNF-α; chemokines including, but not limited to, IP-10, MIG, and MIP-1; binding molecules that immunospecifically bind to a receptor including, but not limited to, the CSF-1 receptor, Flt3, G-CSF receptor, GM-CSF receptor, IFN-α receptor, IFN-β receptor, IFN-γ receptor, IL-1β receptor, IL-2 receptor, IL-3 receptor, IL-4 receptor, IL-5 receptor, IL-6 receptor, IL-7 receptor, IL-8 receptor, IL-9 receptor, IL-10 receptor, IL-12 receptor, IL-15 receptor, IL-18 receptor, IP-10 receptor, M-CSF receptor, MIG receptor, MIP-1 receptor, and TNF-α receptor. Analogs, derivatives or fragments of the above listed compounds which are still functional, i.e. are capable of stimulating and/or activating and/or enhancing and/or augmenting and/or inducing activated immune cells, e.g. activated T-cells such as activated CD4+ T-cells, can also be used as tags of the invention.

Fusion proteins comprising compounds capable of enhancing the immune response and agonistic binding molecules of the invention can be produced by methods known in the art such as, e.g., recombinantly by constructing nucleic acid molecules comprising nucleotide sequences encoding the agonistic binding molecules in frame with nucleotide sequences encoding the suitable compounds and then expressing the nucleic acid molecules. Alternatively, fusion proteins can be produced chemically by conjugating, directly or indirectly via for instance a linker, agonistic binding molecules as defined herein to a suitable compound.

Alternatively, the binding molecules as described in the present invention can be conjugated to tags and be used for detection and/or analytical and/or diagnostic purposes. The tags used to label the binding molecules for those purposes depend on the specific detection/analysis/diagnosis techniques and/or methods used such as inter alia immunohistochemical staining of tissue samples, flow cytometric detection, scanning laser cytometric detection, fluorescent immunoassays, enzyme-linked immunosorbent assays (ELISA's), radioimmunoassays (RIA's), bioassays (e.g., growth inhibition assays), Western blotting applications, etc. For immunohistochemical staining of tissue samples preferred labels are enzymes that catalyze production and local deposition of a detectable product. Enzymes typically conjugated to binding molecules to permit their immunohistochemical visualization are well-known and include, but are not limited to, alkaline phosphatase, P-galactosidase, glucose oxidase, horseradish peroxidase, and urease. Typical substrates for production and deposition of visually detectable products include, but are not limited to, o-nitrophenyl-beta-D-galactopyranoside (ONPG), o-phenylenediamine dihydrochloride (OPD), p-nitrophenyl phosphate (PNPP), p-nitrophenyl-beta-D-galactopryanoside (PNPG), 3′,3′diaminobenzidine (DAB), 3-amino-9-ethylcarbazole (AEC), 4-chloro-1-naphthol (CN), 5-bromo-4-chloro-3-indolyl-phosphate (BCIP), ABTS, BluoGal, iodonitrotetrazolium (INT), nitroblue tetrazolium chloride (NBT), phenazine methosulfate (PMS), phenolphthalein monophosphate (PMP), tetramethyl benzidine (TMB), tetranitroblue tetrazolium (TNBT), X-Gal, X-Gluc, and X-glucoside. Other substrates that can be used to produce products for local deposition are luminescent substrates. For example, in the presence of hydrogen peroxide, horseradish peroxidase can catalyze the oxidation of cyclic diacylhydrazides such as luminol. Next to that, binding molecules of the invention can also be labeled using colloidal gold or they can be labeled with radioisotopes, such as ³³p, ³²p, ³⁵S, ³H, and ¹²⁵I. When the binding molecules of the present invention are used for flow cytometric detections, scanning laser cytometric detections, or fluorescent immunoassays, they can usefully be labeled with fluorophores. A wide variety of fluorophores useful for fluorescently labeling the binding molecules of the present invention include, but are not limited to, Alexa Fluor and Alexa Fluor dyes, BODIPY dyes, Cascade Blue, Cascade Yellow, Dansyl, lissamine rhodamine B, Marina Blue, Oregon Green 488, Oregon Green 514, Pacific Blue, rhodamine 6G, rhodamine green, rhodamine red, tetramethylrhodamine, Cy2, Cy3, Cy3.5, Cy5, Cy5.5, Cy7, fluorescein isothiocyanate (FITC), allophycocyanin (APC), R-phycoerythrin (PE), peridinin chlorophyll protein (PerCP), Texas Red, fluorescence resonance energy tandem fluorophores such as PerCP-Cy5.5, PE-Cy5, PE-Cy5.5, PE-Cy7, PE-Texas Red, and APC-Cy7. When the binding molecules of the present invention are used for secondary detection using labeled avidin, streptavidin, captavidin or neutravidin, the binding molecules may be labeled with biotin.

Next to that, the binding molecules of the invention may be conjugated to photoactive agents or dyes such as fluorescent and other chromogens or dyes to use the so obtained immunoconjugates in photoradiation, phototherapy, or photodynamic therapy. The photoactive agents or dyes include, but are not limited to, photofrin.®, synthetic diporphyrins and dichlorins, phthalocyanines with or without metal substituents, chloroaluminum phthalocyanine with or without varying substituents, O-substituted tetraphenyl porphyrins, 3,1-meso tetrakis(o-propionamido phenyl)porphyrin, verdins, purpurins, tin and zinc derivatives of octaethylpurpurin, etiopurpurin, hydroporphyrins, bacteriochlorins of the tetra(hydroxyphenyl)porphyrin series, chlorins, chlorin e6, mono-1-aspartyl derivative of chlorin e₆, di-1-aspartyl derivative of chlorin e₆, tin(IV) chlorin e₆, meta-tetrahydroxyphenylchlor-in, benzoporphyrin derivatives, benzoporphyrin monoacid derivatives, tetracyanoethylene adducts of benzoporphyrin, dimethyl acetylenedicarboxylate adducts of benzoporphyrin, Diels-Adler adducts, monoacid ring “a” derivative of benzoporphyrin, sulfonated aluminum PC, sulfonated AlPc, disulfonated, tetrasulfonated derivative, sulfonated aluminum naphthalocyanines, naphthalocyanines with or without metal substituents and with or without varying substituents, anthracenediones, anthrapyrazoles, aminoanthraquinone, phenoxazine dyes, phenothiazine derivatives, chalcogenapyrylium dyes, cationic selena and tellurapyrylium derivatives, ring-substituted cationic PC, pheophorbide derivative, naturally occurring porphyrins, hematoporphyrin, ALA-induced protoporphyrin IX, endogenous metabolic precursors, 5-aminolevulinic acid benzonaphthoporphyrazines, cationic imminium salts, tetracyclines, lutetium texaphyrin, tin-etio-purpurin, porphycenes, benzophenothiazinium and combinations thereof.

When the immunoconjugates of the invention are used for in vivo diagnostic use, the binding molecules can also be made detectable by conjugation to e.g. magnetic resonance imaging (MRI) contrast agents, including, but not limited to, agents comprising cobalt (II), copper (II), chromium (III), dysprosium (III), erbium (III), gadolinium (III), holmium (III), iron (II), iron (III), manganese (II), neodymium (III), nickel (II), samarium (III), terbium (III), vanadium (II) or ytterbium (III); ultrasound contrast agents; X-ray contrast agents, including, but not limited to, agents comprising bismuth (III), gold (III), lanthanum (III) or lead (II); or by radioisotopic labeling, including, but not limited to, agents comprising copper⁶⁷, gallium⁶⁷, gallium⁶¹, indium¹¹³, iodine¹²³, iodine¹²⁵, iodine¹³¹, mercury¹⁹⁷, mercury²⁰³, rhenium¹⁸⁶, rhenium¹⁸⁸, rubidium⁹⁷, rubidium¹⁰³, technetium^(99m)or yttrium⁹⁰.

Furthermore, the binding molecules of the invention can also be attached to solid supports, which are particularly useful for immunoassays or purification of the binding partner, i.e. the human OX40-receptor. Such solid supports might be porous or nonporous, planar or nonplanar and include, but are not limited to, glass, cellulose, polyacrylamide, nylon, polystyrene, polyvinyl chloride or polypropylene supports. The binding molecules can also for example usefully be conjugated to filtration media, such as NHS-activated Sepharose or CNBr-activated Sepharose for purposes of immunoaffinity chromatography. They can also usefully be attached to paramagnetic microspheres, typically by biotin-streptavidin interaction. The microspheres can be used for isolation of cells that express or display the human OX40-receptor or fragments thereof. As another example, the binding molecules of the present invention can usefully be attached to the surface of a microtiter plate for ELISA.

It is another aspect of the present invention to provide a nucleic acid molecule encoding at least a binding molecule or functional fragment thereof according to the invention. Such nucleic acid molecules can be used as intermediates for cloning purposes, e.g. in the process of affinity maturation described above. In a preferred embodiment, the nucleic acid molecules are isolated or purified.

The skilled man will appreciate that functional variants of these nucleic acid molecules are also intended to be a part of the present invention. Functional variants are nucleic acid sequences that can be directly translated, using the standard genetic code, to provide an amino acid sequence identical to that translated from the parent nucleic acid molecules. Preferably, the nucleic acid molecules encode agonistic binding molecules comprising a CDR3 region, preferably a heavy chain CDR3 region, comprising an amino acid sequence selected from the group consisting of SEQ ID NO:17 (DRYSQVHYALDY), SEQ ID NO:18 (DRYVNTSNAFDY), SEQ ID NO:19 (DMSGFHEFDY), SEQ ID NO:20 (DRYFRQQNAFDY), SEQ ID NO:21 (ARAAGTIFDY), SEQ ID NO:22 (DRYITLPNALDY), SEQ ID NO:23 (YDEPLTIYWFDS) and SEQ ID NO:24 (YDNVMGLYWFDY). Even more preferably, the nucleic acid molecules encode agonistic binding molecules comprising a heavy chain comprising an amino acid sequence selected from the group consisting of SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27 and SEQ ID NO:28. In yet another embodiment, the nucleic acid molecules encode binding molecules comprising a heavy chain comprising the amino acid sequence of SEQ ID NO:25 and a light chain comprising the amino acid sequence of SEQ ID NO:29, or they encode a heavy chain comprising the amino acid sequence of SEQ ID NO:26 and a light chain comprising the amino acid sequence of SEQ ID NO:30, or they encode a heavy chain comprising the amino acid sequence of SEQ ID NO:27 and a light chain comprising the amino acid sequence of SEQ ID NO:31, or they encode a heavy chain comprising the amino acid sequence of SEQ ID NO:28 and a light chain comprising the amino acid sequence of SEQ ID NO:32. A further aspect of the invention pertains to nucleic acid molecules comprising a nucleotide sequence selected from the group consisting of SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41 and SEQ ID NO:42. Nucleic acid molecules comprising a heavy chain comprising the nucleotide sequence of SEQ ID NO:39 and a light chain comprising the nucleotide sequence of SEQ ID NO:43, a heavy chain comprising the nucleotide sequence of SEQ ID NO:40 and a light chain comprising the nucleotide sequence of SEQ ID NO:44, a heavy chain comprising the nucleotide sequence of SEQ ID NO:41 and a light chain comprising the nucleotide sequence of SEQ ID NO:45 or a heavy chain comprising the nucleotide sequence of SEQ ID NO:42 and a light chain comprising the nucleotide sequence of SEQ ID NO:46 are also a part of the present invention.

Another aspect of nucleic acid molecules according to the present invention, is their potential for use in gene-therapy or vaccination applications. Therefore, in another embodiment of the invention, nucleic acid molecules according to the invention are provided wherein said nucleic acid molecule is present in a gene delivery vehicle. A ‘gene delivery vehicle’ as used herein refers to an entity that can be used to introduce nucleic acid molecules into cells, and includes liposomes, recombinant viruses, and the like. Preferred gene therapy vehicles of the present invention will generally be viral vectors, such as comprised within a recombinant retrovirus, herpes simplex virus (HSV), adenovirus, adeno-associated virus (AAV), cytomegalovirus (CMV), and the like. Such applications of the nucleic acid sequences according to the invention are included in the present invention. The person skilled in the art will be aware of the possibilities of recombinant viruses for administering sequences of interest to cells. The administration of the nucleic acids of the invention to cells can result in an enhanced immune response.

It is another aspect of the invention to provide vectors, i.e. nucleic acid constructs, comprising one or more nucleic acid molecules according to the present invention. Vectors can be derived from plasmids such as inter alia F, R1, RP1, Col, pBR322, TOL, Ti, etc; cosmids; phages such as lambda, lambdoid, M13, Mu, P1, P22, Qβ, T-even, T-odd, T2, T4, T7, etc; plant viruses such as inter alia alfalfa mosaic virus, bromovirus, capillovirus, carlavirus, carmovirus, caulivirus, clostervirus, comovirus, cryptovirus, cucumovirus, dianthovirus, fabavirus, fijivirus, furovirus, geminivirus, hordeivirus, ilarvirus, luteovirus, machlovirus, marafivirus, necrovirus, nepovirus, phytorepvirus, plant rhabdovirus, potexvirus, potyvirus, sobemovirus, tenuivirus, tobamovirus, tobravirus, tomato spotted wilt virus, tombusvirus, tymovirus, etc; or animal viruses such as inter alia adenovirus, arenaviridae, baculoviridae, birnaviridae, bunyaviridae, calciviridae, cardioviruses, coronaviridae, corticoviridae, cystoviridae, Epstein-Barr virus, enteroviruses, filoviridae, flaviviridae, Foot-and-Mouth disease virus, hepadnaviridae, hepatitis viruses, herpesviridae, immunodeficiency viruses, influenza virus, inoviridae, iridoviridae, orthomyxoviridae, papovaviruses, paramyxoviridae, parvoviridae, picornaviridae, poliovirus, polydnaviridae, poxviridae, reoviridae, retroviruses, rhabdoviridae, rhinoviruses, Semliki Forest virus, tetraviridae, togaviridae, toroviridae, vaccinia virus, vescular stomatitis virus, etc. Vectors can be used for cloning and/or for expression of the agonistic binding molecules of the invention and might even be used for gene therapy purposes. Vectors comprising one or more nucleic acid molecules according to the invention operably linked to one or more expression-regulating nucleic acid molecules are also covered by the present invention. The choice of vector is dependent on the recombinant procedures followed and the host used. Introduction of vectors in host cells can be effected by inter alia calcium phosphate transfection, virus infection, DEAE-dextran mediated transfection, lipofectamin transfection or electroporation. Vectors may be autonomously replicating or may replicate together with the chromosome into which they have been integrated. Preferably, the vectors contain one or more selection markers. Useful markers are dependent on the host cells of choice and are well known to persons skilled in the art. They include, but are not limited to, kanamycin, neomycin, puromycin, hygromycin, zeocin, thymidine kinase gene from Herpes simplex virus (HSV-TK), dihydrofolate reductase gene from mouse (dhfr). Vectors comprising one or more nucleic acid molecules encoding the agonistic binding molecules as described above operably linked to one or more nucleic acid molecules encoding proteins or peptides that can be used to isolate the binding molecules are also covered by the invention. These proteins or peptides include, but are not limited to, glutathione-S-transferase, maltose binding protein, metal-binding polyhistidine, green fluorescent protein, luciferase and beta-galactosidase.

Hosts containing one or more copies of the vectors mentioned above are an additional subject of the present invention. Preferably, the hosts are host cells. Host cells include, but are not limited to, cells of mammalian, plant, insect, fungal or bacterial origin. Bacterial cells include, but are not limited to, cells from Gram positive bacteria such as several species of the genera Bacillus, Streptomyces and Staphylococcus or cells of Gram negative bacteria such as several species of the genera Escherichia and Pseudomonas. In the group of fungal cells preferably yeast cells are used. Expression in yeast can be achieved by using yeast strains such as inter alia Pichia pastoris, Saccharomyces cerevisiae and Hansenula polymorpha. Furthermore, insect cells such as cells from Drosophila and Sf9 can be used as host cells. Besides that, the host cells can be plant cells such as inter alia cells from crop plants such as forestry plants, or cells from plants providing food and raw materials such as cereal plants, or medicinal plants, or cells from ornamentals, or cells from flower bulb crops. Transformed (transgenic) plants or plant cells are produced by known methods, for example, Agrobacterium-mediated gene transfer, transformation of leaf discs, protoplast transformation by polyethylene glycol-induced DNA transfer, electroporation, sonication, microinjection or bolistic gene transfer. Additionally, a suitable expression system can be a baculovirus system. Expression systems using mammalian cells such as Chinese Hamster Ovary (CHO) cells, COS cells, BHK cells or Bowes melanoma cells are preferred in the present invention. Mammalian cells provide expressed proteins with posttranslational modifications that are most similar to natural molecules of mammalian origin. Since the present invention deals with molecules that may have to be administered to humans, a completely human expression system would be particularly preferred. Therefore, even more preferably, the host cells are human cells, such as HeLa, 911, AT1080, A549, 293 or PER.C6™ cells (PER.C6 is a trademark owned by Crucell Holland B. V.) and cells derived therefrom by genetic modification with antibody encoding expression constructs. In preferred embodiments, the producing human cells comprise at least a functional part of a nucleic acid sequence encoding an adenovirus E1 region in expressible format. In even more preferred embodiments, said host cells are derived from a human retina and immortalized with nucleic acids comprising adenoviral E1 sequences, such as PER.C6™ cells and derivatives thereof. Production of recombinant proteins in host cells can be performed according to methods well known in the art. The use of PER.C6™ cells as a production platform for proteins of interest has been described in WO 00/63403 the disclosure of which is incorporated herein by reference.

It is another aspect of the invention to provide a method of producing agonistic binding molecules or functional variants thereof, preferably human agonistic binding molecules or functional variants thereof according to the present invention. The method comprises the steps of a) culturing a host as described above under conditions conducive to the expression of the agonistic binding molecules, and b) optionally, recovering the expressed agonistic binding molecules. The expressed agonistic binding molecules can be recovered from the cell free extract, but preferably they are recovered from the culture medium. Methods to recover proteins, such as binding molecules, from cell free extracts or culture medium are well known to the man skilled in the art. Agonistic binding molecules or functional variants thereof as obtainable by the above described method are also a part of the present invention.

Alternatively, next to the expression in hosts, such as host cells, the agonistic binding molecules of the invention or functional fragments thereof can be produced synthetically by conventional peptide synthesizers or in cell-free translation systems using RNA's derived from DNA molecules according to the invention. Agonistic binding molecule as obtainable by the above described synthetic production methods or cell-free translation systems are also a part of the present invention.

In yet another alternative embodiment, binding molecules according to the present invention, preferably human agonistic binding molecules specifically binding to the human OX40-receptor or fragments thereof, may be generated by transgenic non-human mammals, such as for instance transgenic mice or rabbits, that express human immunoglobulin genes. Preferably, the transgenic non-human mammals have a genome comprising a human heavy chain transgene and a human light chain transgene encoding all or a portion of the human agonistic binding molecules as described above. The transgenic non-human mammals can be immunized with a purified or enriched preparation of the human OX40-receptor or fragment thereof and/or cells expressing the human OX40-receptor. Protocols for immunizing non-human mammals are well established in the art. See Using Antibodies: A Laboratory Manual, Edited by: E. Harlow, D. Lane (1998), Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. and Current Protocols in Immunology, Edited by: J. E. Coligan, A. M. Kruisbeek, D. H. Margulies, E. M. Shevach, W. Strober (2001), John Wiley & Sons Inc., New York, the disclosures of which are incorporated herein by reference. Immunization protocols often include multiple immunizations, either with or without adjuvants such as Freund's complete adjuvant and Freund's incomplete adjuvant, but may also include naked DNA immunizations. In another embodiment, the human agonistic binding molecules are produced by B cells or plasma cells derived from the transgenic animals. In yet another embodiment, the human agonistic binding molecules are produced by hybridomas which are prepared by fusion of B cells obtained from the above described transgenic non-human mammals to immortalized cells. B cells, plasma cells and hybridomas as obtainable from the above described transgenic non-human mammals and human agonistic binding molecules as obtainable from the above described transgenic non-human mammals, B cells, plasma cells and hybridomas are also a part of the present invention. In yet another embodiment, human agonistic binding molecules of the present invention can also be produced in transgenic, non-human, mammals such as inter alia goats or cows, and can be secreted into, and optionally recovered from, the milk of the transgenic mammals.

In a further aspect, the invention provides a method of identifying binding molecules, preferably human binding molecules such as human monoclonal antibodies or fragments thereof, according to the invention or nucleic acid molecules according to the invention and comprises the steps of a) contacting a phage library of binding molecules, preferably human binding molecules, with material comprising the human OX40-receptor or a part thereof, b) selecting at least once for a phage binding to the material comprising the human OX40-receptor or a part thereof, and c) separating and recovering the phage binding to the material comprising the human OX40-receptor or a part thereof. The selection step according to the present invention is preferably performed in the presence of at least part of the human OX40-receptor, e.g. cells transfected with the human OX40-receptor expression plasmids, isolated human OX40-receptor, the extracellular part thereof, fusion proteins comprising such, and the like.

Phage display methods for identifying and obtaining binding molecules, e.g. antibodies, are by now well-established methods known by the person skilled in the art. They are e.g. described in U.S. Pat. No. 5,696,108; Burton and Barbas, 1994; and de Kruif et al., 1995b. For the construction of phage display libraries, collections of human monoclonal antibody heavy and light chain variable region genes are expressed on the surface of bacteriophage, preferably filamentous bacteriophage, particles, in for example single chain Fv (scFv) or in Fab format (see de Kruif et al., 1995b). Large libraries of antibody fragment-expressing phages typically contain more than 1.0×10⁹ antibody specificities and may be assembled from the immunoglobulin V regions expressed in the B lymphocytes of immunized- or non-immunized individuals. Alternatively, phage display libraries may be constructed from immunoglobulin variable regions that have been partially assembled in vitro to introduce additional antibody diversity in the library (semi-synthetic libraries). For example, in vitro assembled variable regions contain stretches of synthetically produced, randomized or partially randomized DNA in those regions of the molecules that are important for antibody specificity, e.g. CDR regions. Antigen specific phage antibodies can be selected from the library by immobilizing target antigens such as the human OX40-receptor or fragments thereof on a solid phase and subsequently exposing the target antigens to a phage library to allow binding of phages expressing antibody fragments specific for the solid phase-bound antigen. Non-bound phages are removed by washing and bound phages eluted from the solid phase for infection of Escherichia coli (E. coli) bacteria and subsequent propagation. Multiple rounds of selection and propagation are usually required to sufficiently enrich for phages binding specifically to the target antigen. Phages may also be selected for binding to complex antigens such as complex mixtures of proteins or whole cells such as cells transfected with the human OX40-receptor expression plasmids or cells naturally expressing the human OX40-receptor. Selection of antibodies on whole cells has the advantage that target antigens are presented in their native configuration, i.e. unperturbed by possible conformational changes that might have been introduced in the case where an antigen is immobilized to a solid phase. Antigen specific phage antibodies can be selected from the library by incubating a cell population of interest, expressing known and unknown antigens on their surface, with the phage antibody library to let for example the scFv or Fab part of the phage bind to the antigens on the cell surface. After incubation and several washes to remove unbound and loosely attached phages, the cells of interest are stained with specific fluorescent labeled antibodies and separated on a Fluorescent Activated Cell Sorter (FACS). Phages that have bound with their scFv or Fab part to these cells are eluted and used to infect Escherichia coil to allow amplification of the new specificity. Generally, one or more selection rounds are required to separate the phages of interest from the large excess of non-binding phages. Monoclonal phage preparations can be analyzed for their specific staining patterns and allowing identification of the antigen being recognized (De Kruif et al., 1995a; Lekkerkerker and Logtenberg, 1999). The phage display method can be extended and improved by subtracting non-relevant binders during screening by addition of an excess of non-target molecules that are similar but not identical to the target, and thereby strongly enhance the chance of finding relevant binding molecules (see U.S. Pat. No. 6,265,150 which is incorporated herewith by reference). In this method, subtraction can be done by the presence of T-cells and other lymphocytes that do not express the human OX40-receptor.

In yet a further aspect, the invention provides a method of obtaining a binding molecule, preferably a human binding molecule or a nucleic acid molecule according to the invention, wherein the method comprises the steps of a) performing the above described method of identifying binding molecules, preferably human binding molecules such as human monoclonal antibodies or fragments thereof according to the invention, or nucleic acid molecules according to the invention, and b) isolating from the recovered phage the human binding molecule and/or the nucleic acid encoding the human binding molecule. Once a new monoclonal phage antibody has been established or identified with the above mentioned method of identifying binding molecules or nucleic acid molecules encoding the binding molecules, the DNA encoding the scFv or Fab can be isolated from the bacteria or phages and combined with standard molecular biological techniques to make constructs encoding bivalent scFv's or complete human immunoglobulins of a desired specificity (e.g. IgG, IgA or IgM). These constructs can be transfected into suitable cell lines and complete binding molecules such as human monoclonal antibodies can be produced (see Huls et al., 1999; Boel et al., 2000).

Preferably, after identifying and obtaining a binding molecule specifically binding to the human OX40-receptor, it is established if the binding molecule has agonistic activity. This can be tested in vitro in a cell culture system or in an animal model system. The cell culture system can comprise cells derived from a tissue sample of a patient. For instance, activated CD4+ T-cells can be contacted with a binding molecule of the invention or a control binding molecule and the ability of the binding molecule of the invention to enhance the activity of activated CD4+ T-cells compared to the control binding molecule can be determined. Furthermore, the activation induced by the binding molecule of the invention might be compared to a well-known inducer of the OX40-receptor such as the OX40-ligand. Moreover, with this kind of test a binding molecule with antagonistic activity can be identified and optionally used in the treatment of a disorder or disease wherein antagonistic binding molecules capable of binding to the human OX40-receptor are useful. The ability of binding molecule according to the invention to modulate (either enhance or decrease) the activity of activated CD4+ T-cells can be assessed by detecting the proliferation of CD4+ T-cells, detecting the activation of signaling molecules, detecting the effector function of CD4+ T-cells, detecting the expression of cytokines or antigens, or detecting the differentiation of CD4+ T-cells. Furthermore, agonistic activity of the binding molecules can be established by a costimulation assay with for instance the OX40-ligand as described in the present examples. Techniques known to those of skill in the art can be used for measuring these activities. For example, cellular proliferation can be assayed by ³H-thymidine incorporation assays and trypan blue cell counts. The activation of signaling molecules can be assayed, for example, by kinase assays and electromobility shift assays (EMSAs). The effector function of T-cells can be measured, for example, by cytokine ELISA assays or elispot assays. Cytokine and antigen expression can be assayed, for example, by immunoassays including, but not limited to, competitive and non-competitive assay systems using techniques such as Western blots, immunohistochemistry, radioimmunoassays, ELISA, sandwich immunoassays, immunoprecipitation assays, immunodiffusion assays, agglutination assays, complement-fixation assays, immunoradiometric assays, fluorescent immunoassays, protein A immunoassays and FACS analysis. The binding molecules of the invention can also be tested in suitable animal model systems prior to use in humans. Such animal model systems include, but are not limited to, mice, rats, chicken, cows, monkeys, pigs, dogs, rabbits, etc. Any animal system well-known in the art may be used.

In a further aspect, the invention provides compositions comprising at least one agonistic binding molecule, at least one functional variant or fragment thereof, at least one immunoconjugate according to the invention or a combination thereof. In addition to that, the compositions may comprise inter alia stabilizing molecules, such as albumin or polyethylene glycol, or salts. Preferably, the salts used are salts that retain the desired biological activity of the binding molecules and do not impart any undesired toxicological effects. Examples of such salts include, but are not limited to, acid addition salts and base addition salts. Acid addition salts include, but are not limited to, those derived from nontoxic inorganic acids, such as hydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydro-iodic, and phosphorous acids and the like, as well as from nontoxic organic acids such as aliphatic mono- and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids, aromatic acids, aliphatic and aromatic sulfonic acids and the like. Base addition salts include, but are not limited to, those derived from alkaline earth metals, such as sodium, potassium, magnesium, calcium and the like, as well as from nontoxic organic amines, such as N,N′-dibenzylethylenediamine, N-methylglucamine, chloroprocaine, choline, diethanolamine, ethylenediamine, procaine and the like. If necessary, the binding molecules of the invention may be coated in or on a material to protect them from the action of acids or other natural or non-natural conditions that may inactivate the binding molecules.

In yet a further aspect, the invention provides compositions comprising at least one nucleic acid molecule as defined in the present invention. The compositions may comprise aqueous solutions such as aqueous solutions containing salts (e.g., NaCl or salts as described above), detergents (e.g., SDS) and/or other suitable components.

Furthermore, the present invention pertains to pharmaceutical compositions comprising at least one agonistic binding molecule according to the invention, at least one functional variant or fragment thereof, at least one immunoconjugate according to the invention, at least one composition according to the invention, or combinations thereof. The pharmaceutical composition of the invention further comprises at least one pharmaceutically acceptable excipient. A pharmaceutical composition according to the invention can further comprise at least one other therapeutic, prophylactic and/or diagnostic agent. Alternatively, the further therapeutic, prophylactic and/or diagnostic agents can also be administered separately from the pharmaceutical composition of the invention. The pharmaceutical compositions of the invention can be used in vitro, ex vivo or in vivo. Therapeutic agents and prophylactic agents can include, but are not limited to, toxic substances, radioactive substances, liposomes, binding molecules (with or without tags) specifically binding to cancer cell antigens, enzymes, polynucleotide sequences, plasmids, proteins, peptides or combinations thereof. Toxic substances include, but are not limited to, cytotoxic agents, such as small molecule toxins or chemotherapeutic agents, or enzymatically active toxins of bacterial, fungal, plant or animal origin, or fragments thereof. In general, suitable chemotherapeutic agents are described in Remington's Pharmaceutical Sciences, 18^(th) edition (1990), Edited by: A. R. Gennaro, Mack Publishing Co., Philadelphia and in Goodman and Gilman's The Pharmacological Basis of Therapeutics, 7th edition (1985), Edited by: A. G. Gilman, L. S. Goodman, T. W. Rall and F. Murad. MacMillan Publishing Co., New York. Suitable chemotherapeutic agents that are still in the experimental phase are known to those of skill in the art and might also be used as toxic substances in the present invention. In a specific embodiment, therapeutic agents and prophylactic agents can include, but are not limited to, compounds that stimulate and/or activate and/or enhance and/or augment and/or induce activated immune cells, e.g. activated T-cells such as activated CD4+ T-cells. Such compounds may include, but are not limited to, binding molecules, small molecules, organic or inorganic compounds, enzymes, polynucleotide sequences, plasmids, proteins, peptides, liposomes or combinations thereof. Examples of compounds capable of enhancing the immune response include, but are not limited to, compounds that activate a cytokine receptor such as inter alia cytokines including, but not limited to, CSF-1, Flt3 ligand, G-CSF, GM-CSF, IFN-α, IFN-β, IFN-γ, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-15, IL-18, M-CSF, and TNF-α; chemokines including, but not limited to, IP-10, MIG, and MIP-1; binding molecules that immunospecifically bind to the CSF-1 receptor, Flt3, G-CSF receptor, GM-CSF receptor, IFN-α receptor, IFN-β receptor, IFN-γ receptor, IL-1β receptor, IL-2 receptor, IL-3 receptor, IL-4 receptor, IL-5 receptor, IL-6 receptor, IL-7 receptor, IL-8 receptor, IL-9 receptor, IL-10 receptor, IL-12 receptor, IL-15 receptor, IL-18 receptor, IP-10 receptor, M-CSF receptor, MIG receptor, MIP-1 receptor, and TNF-α receptor. Pharmaceutically acceptable salts, acids or derivatives, analogs, derivatives or fragments of the above listed compounds which are still functional, i.e. are capable of stimulating and/or activating and/or enhancing and/or augmenting and/or inducing activated immune cells, e.g. activated T-cells such as activated CD4+ T-cells, can also be used as further therapeutic or prophylactic agents. In a specific embodiment of the invention the pharmaceutical composition of the invention comprises an OX40-ligand, preferably a human OX40-ligand. This ligand can also be administered separately, either before, subsequent to, or after administration of the pharmaceutical composition of the invention.

Alternatively, the further therapeutic or prophylactic agents include, but are not limited to, anti-viral, anti-microbial, such as anti-bacterial, or anti-fungal agents. Such agents can be binding molecules, small molecules, organic or inorganic compounds, enzymes, polynucleotide sequences etc. Examples of anti-microbial agents include, but are not limited to, amifloxacin, amikacin, amoxicillin, amphotericin B, ampicillin, azlocillin, aztreonam, bacampicillin, bacitracin, bifonazole, cafamandole, candicidin, carbenicillin, carbenicillin indanyl, cefaclor, cefadroxil, cefazolin, cefepime, cefonicid, cefoparazone, ceforanide, cefotaxime, cefotetan, cefoxitin, cefpodoxime proxetil, ceftazidime, ceftizoxime, ceftriaxone, cefuroxime, cefuroxime axetil, cepalospolin, cephadrine, cephalexin, cephalothin, chlortetracycline, cinoxacin, ciprofloxacin, clavulanic acid, cloxacillin, clotrimazole, demeclocycline, dicloxacillin, doxycycline, econazole, erythromycin, fleroxacin, floxacillin, 5-fluorocytosine, fluconazole, gentamicin, griseofulvin, haloprogin, imipenem, itraconazole, kanamycin, ketoconazole, lomefloxacin, loracarbef, methacycline, methicillin, metronidazole, mezlocillin, miconazole, minocycline, moxalactam, nafcillin, natamycin, neomycin, netilmicin, norfloxacin, nystatin, ofloxacin, oxacillin, oxytetracycline, para-aminobenzoic acid, pefloxacin, penicillin G, penicillin V, pentamidine, piperacillin, sparfloxacin, streptomycin, sulfacetamide, sulfadiazine, sulfamethoxazole, sulfanilamide, sulfisoxazole, tetracycline, ticarcillin, tobramycin, trimethoprim-sulfamethoxazole nalidixic acid, vancomycin, vibunazole, and pharmaceutically acceptable salts, acids or derivatives of any of the above.

Examples of anti-viral agents include, but are not limited to, abacavir, acyclovir, adefovir, afovirsen, amantadine, amprenavir, AZT, camptothecins, castanospermine, cidofovir, D4T, ddC, ddI, d4T, delavirdine, didanosine, efavirenz, famciclovir, fialuridine, foscarnet, FTC, ganciclovir, GG167, idoxuridine, indinavir, interferon alpha, lamivudine, lobucavir, loviride, nelfinavir, nevirapine, oseltamivir, penciclovir, pirodavir, ribavirin, rimantadine, ritonavir, saquinavir, sICAM-1, sorivudine, stavudine, trifluridine, 3TC, valacyclovir, vidarabine, zalcitabine, zanamivir, zidovudine, and pharmaceutically acceptable salts, acids or derivatives of any of the above.

Examples of anti-fungal agents include, but are not limited to, amphotericin B, benzoic acid, butoconazole, caprylic acid, ciclopirox olamine, clotrimazole, econazole, fluconazole, flucytosine, griseofulvin, haloprogin, imidazoles, itraconzole, ketoconazole, miconazole, naftifine, nystatin, potassium iodide, propionic acid, salicyclic acid, terbinafine, terconazole, tolnaftate, and triazoles, undecylenic acid, and pharmaceutically acceptable salts, acids or derivatives of any of the above.

Typically, pharmaceutical compositions must be sterile and stable under the conditions of manufacture and storage. The agonistic binding molecules, variant or fragments thereof, immunoconjugates, nucleic acid molecules or compositions of the present invention can be in powder form for reconstitution in the appropriate pharmaceutically acceptable excipient before or at the time of delivery. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying (lyophilization) that yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.

Alternatively, the agonistic binding molecules, variant or fragments thereof, immunoconjugates, nucleic acid molecules or compositions of the present invention can be in solution and the appropriate pharmaceutically acceptable excipient can be added and/or mixed before or at the time of delivery to provide a unit dosage injectable form. Preferably, the pharmaceutically acceptable excipient used in the present invention is suitable to high drug concentration, can maintain proper fluidity and, if necessary, can delay absorption.

The choice of the optimal route of administration of the pharmaceutical compositions will be influenced by several factors including the physico-chemical properties of the active molecules within the compositions, the urgency of the clinical situation and the relationship of the plasma concentrations of the active molecules to the desired therapeutic effect. For instance, if necessary, the agonistic binding molecules of the invention can be prepared with carriers that will protect them against rapid release, such as a controlled release formulation, including implants, transdermal patches, and microencapsulated delivery systems. Biodegradable, biocompatible polymers can inter alia be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Furthermore, it may be necessary to coat the agonistic binding molecules with, or co-administer the agonistic binding molecules with, a material or compound that prevents the inactivation of the agonistic binding molecules. For example, the agonistic binding molecules may be administered to a subject in an appropriate carrier, for example, liposomes, or a diluent.

The routes of administration can be divided into two main categories, oral and parenteral administration. These two categories include, but are not limited to, bolus, buccal, epidermal, epidural, inhalation, intra-abdominal, intra-arterial, intra-articular, intrabronchial, intracapsular, intracardiac, intracartilaginous, intracavitary, intracelial, intracelebellar, intracerebronventricular, intracolic, intracervical, intradermal, intragastric, intrahepatic, intramedullary, intramuscular, intramyocardial, intranasal, intra-ocular intra-orbital, intra-osteal, intrapelvic, intrapericardiac, intraperitoneal, intraplaque, intrapleural, intraprostatic, intrapulmonary, intrarectal, intrarenal, intraretinal, intraspinal, intrasternal, intrasynovial, intrathecal, intrathoracic, intratumoral, intra-uterine, intravenous, intraventricular, intravesical, rectal, spinal, subarachnoid, subcapsular, subcutaneous, subcuticular, sublingual, topical, transdermal, and transmucosal, transtracheal, vaginal administration.

Oral dosage forms can be formulated inter alia as tablets, troches, lozenges, aqueous or oily suspensions, dispersable powders or granules, emulsions, hard capsules, soft gelatin capsules, syrups or elixirs, pills, dragees, liquids, gels, or slurries. These formulations can contain pharmaceutically acceptable excipients including, but not limited to, inert diluents such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents such as corn starch or alginic acid; binding agents such as starch, gelatin or acacia; lubricating agents such as calcium stearate, glyceryl behenate, hydrogenated vegatable oils, magnesium stearate, mineral oil, polyethylene glycol, sodium stearyl, fumarate, stearic acid, talc, zinc stearate; preservatives such as n-propyl-p-hydroxybenzoate; colouring, flavouring or sweetening agents such as sucrose, saccharine, glycerol, propylene glycol or sorbitol; vegetable oils such as arachis oil, olive oil, sesame oil or coconut oil; mineral oils such as liquid parrafin; wetting agents such as benzalkonium chloride, docusate sodium, lecithin, poloxamer, sodium lauryl sulfate, sorbitan esters; and thickening agents such as agar, alginic acid, beeswax, carboxymethyl cellulose calcium, carageenan, dextrin or gelatin.

The pharmaceutical compositions of the present invention can also be formulated for parenteral administration. Formulations for parenteral administration can be inter alia in the form of aqueous or non-aqueous isotonic sterile non-toxic injection or infusion solutions or suspensions. Preferred parenteral administration routes include intravenous, intraperitoneal, epidural, intramuscular and intratumoral injection or infusion. The solutions or suspensions may comprise agents that are non-toxic to recipients at the dosages and concentrations employed such as 1,3-butanediol, Ringer's solution, Hank's solution, isotonic sodium chloride solution, oils such as synthetic mono- or diglycerides or fatty acids such as oleic acid, local anaesthetic agents, preservatives, buffers, viscosity or solubility increasing agents, water-soluble antioxidants such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite and the like, oil-soluble antioxidants such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, alpha-tocopherol, and the like, and metal chelating agents, such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, and the like.

In a further aspect, the invention encompasses the use of an agonistic binding molecule, a functional variant, an immunoconjugate, a nucleic acid molecule, a composition or a pharmaceutical composition of the invention for stimulating T-cells, preferably activated CD4+ T-cells in vitro. The agonistic binding molecules of the invention can also be contacted together with antigen-presenting cells with T-cells to stimulate T-cell proliferation in vitro.

The agonistic binding molecules, preferably the human agonistic binding molecules such as human agonistic monoclonal antibodies according to the invention, the variants or fragments thereof, the immunoconjugates according to the invention, the nucleic acid molecules according to the invention, the compositions according to the invention or the pharmaceutical compositions according to the invention can be used as medicaments. They can inter alia be used in the diagnosis, prophylaxis, treatment, or combination thereof, of a neoplastic, viral, or bacterial disorder or disease. Preferably, the neoplastic disorder or disease is selected from the group consisting of heavy chain disease, leukemias (e.g., acute myeloid leukemia, chronic myeloid leukemia, chronic myelomonocytic leukemia, acute promyelocytic leukemia, myelodysplastic syndrome, juvenile myelomonocytic leukemia, etc.), metastases, neoplasms, tumors (e.g., acoustic neuroma, adenocarcinoma, adrenal cortical cancer, anal carcinoma, angiosarcoma, astrocytoma, basal cell carcinoma, bile duct carcinoma, bladder carcinoma, brain cancer, breast cancer, bronchogenic carcinoma, cancer of the peritoneum, cervical cancer, chondrosarcoma, chordoma, choriocarcinoma, colon carcinoma, colorectal cancer, craniopharyngioma, cystadenocarcinoma, embryonal carcinoma, endometrial carcinoma, endotheliosarcoma, ependymoma, epithelial carcinoma, esophageal cancer, Ewing's tumor, fibrosarcoma, gastrointestinal cancer, genitourinary tract cancer, glioblastoma, glioma, head cancer, hemangioblastoma, hepatoma, Hodgkin's Disease, kidney cancer, leiomyosarcoma, liposarcoma, liver cancer, lung carcinoma, lymphangioendotheliosarcoma, lymphangiosarcoma, lymphomas, malignant hypercalcemia, malignant pancreatic insulanoma, medullary carcinoma, medulloblastoma, melanoma, meningioma, mesothelioma, neck cancer, neuroblastoma, non-Hodgkin's lymphoma, non-small cell lung carcinoma, oligodendroglioma, osteogenic sarcoma, ovarian cancer, pancreatic cancer, papillary adenocarcinomas, papillary carcinoma, penile carcinoma, pinealoma, premalignant skin lesions, primary brain tumors, primary macroglobulinemia, primary thrombocytosis, prostate cancer, rectal cancer, renal cell carcinoma, retinoblastoma, rhabdomyosarcoma, salivary gland carcinoma, sarcoma, sebaceous gland carcinoma, seminoma, small cell lung carcinoma, squamous cell carcinoma, stomach cancer, synovioma, sweat gland carcinoma, testicular tumor, thyroid cancer, uterine carcinoma, vulval cancer, and Wilms tumor), or any disease or disorder characterized by uncontrolled cell growth. The binding molecules of the invention are suitable for treatment of yet untreated patients suffering from any of the above disorders and diseases, patients who have been or are treated and are in remission or are not in remission, and patients with a recurrent/refractory diseases or disorders.

Preferably, the viral disorder or disease is selected from the group consisting of disorders or diseases associated with the coronavirus responsible for the Severe Acute Respiratory Syndrome (SARS), herpes simplex virus (HSV), hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphotrophic virus (HTLV) type I and II, human immunodeficiency virus (HIV) type I and II, cytomegalovirus, papillomavirus, polyoma viruses, adenoviruses, Epstein-Barr virus, poxviruses, influenza virus, measles virus, rabies virus, Sendai virus, poliomyelitis virus, coxsackieviruses, rhinoviruses, reoviruses, and rubella virus.

Preferably, the bacterial (for sake of simplicity also including yeast and fungal disorders and diseases) disorder or disease is selected from the group consisting of disorders or diseases associated with Acinetobacter sp., Aeromonas hydrophila, Alcaligenes faecalis, Bacillus cereus, Bacteroides fragilis, Bacteroides ovatus, Bacteroides ureolyticus, Bacteroides vulgatus, Borrelia burgdorferi, Borrelia vincentii, Brucella abortus, Brucella melitensis, Brucella suis, Campylobacter (Vibrio) fetus, Campylobacter jejuni, Chlamydia spp., Citrobacter diversus, Citrobacter freundii, Corynebacterium jeikeium, Clostridium botulinum, Clostridium difficile, Clostridium perfringens, Clostridium ramosum, Clostridium sporogenes, Clostridium sp., Clostridium tetani, Corynebacterium diphtheriae, Edwardsiella tarda, Enterobacter aerogenes, Enterobacter cloacae, Enterococcus faecalis, Escherichia coli, Francisella tularensis, Haemophilus influenzae, Helicobacter pylori, Klebsiella oxytoca, Klebsiella ozaenae, Klebsiella pneumoniae, Klebsiella rhinoscleromotis, Leptospira icterohemorrhagiae, Mycobacterium tuberculosis, Mycoplasma spp., Neisseria gonorrhoea, Neisseria meningitidis, Peptostreptococcus anaerobius, Peptostreptococcus asaccharolyticus, Peptostreptococcus magnus, Pneumocystis carinii, Prevotella bivia, and Prevotella melaninogenica, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas stutzeri, Rickettsia prowazeki, Rickettsia tsutsugumushi, Salmonella typhimurium, Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus group C, Streptococcus group G, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus simulans, Staphylococcus warneri, Staphylococcus xylosus, Stenotrophomonas maltophilia, Streptococcus agalactiae, Streptococcus bovis, Streptococcus equinus, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus pyogenes, Toxoplasma gondii, Treponema carateneum, Treponema pallidum, Treponema pertenue, Vibrio cholerae, Yersinia enterocolitica, Yersinia pestis, and Yersinia pseudotuberculosis.

Preferably, the agonistic binding molecules, preferably the human agonistic binding molecules such as human agonistic monoclonal antibodies according to the invention, the variants or fragments thereof, the immunoconjugates according to the invention, the nucleic acid molecules according to the invention, the compositions according to the invention or the pharmaceutical compositions according to the invention can be used for enhancing the immune response in a human or animal, more preferably for enhancing the immune response against a tumour, bacterial or viral antigen in a human or animal. In a specific embodiment the agonistic binding molecules of the invention can be used in combination with the OX40-ligand, preferably the human OX40-ligand. These compounds may exert a costimulatory effect.

As a further aspect, the invention encompasses a method for modulating a T-cell response in a human, comprising the step of administering to said human an effective dose of a binding molecule according to the invention or a functional variant according to the invention, an immunoconjugate according to the invention, a nucleic acid molecule according to the invention, a vector according to the invention or a pharmaceutical composition according to the invention. Preferably, said modulation comprises the stimulation of T-cell proliferation.

Another aspect of the invention covers the use of an agonistic binding molecule, a functional variant, an immunoconjugate, a nucleic acid molecule, a composition or a pharmaceutical composition for the preparation of a medicament for the treatment of a neoplastic, viral or bacterial disorder or a disease as described herein. More preferably, the use will be for the preparation of a medicament for enhancing the immune response in a human or animal, more preferably the use will be for the preparation of a medicament for enhancing the immune response against a tumour, bacterial or viral antigen in a human or animal.

The molecules are typically formulated in the compositions and pharmaceutical compositions of the invention in a therapeutically, prophylactically or diagnostically effective amount such as for instance 1-100 mg/kg, preferably 1-25 mg/kg, more preferably 3-10 mg/kg. Dosage regimens can be adjusted to provide the optimum desired response (e.g., a therapeutic response). For example, a single bolus may be administered, several divided doses may be administered over time or the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation. The molecules and compositions according to the present invention are preferably sterile. Methods to render these molecules and compositions sterile are well known in the art.

Alternatively, cells that are genetically engineered to express the human agonistic binding molecules of the invention are administered to patients in vivo. Such cells may be obtained from an animal or patient or an MHC compatible donor and can include, but are not limited to fibroblasts, bone marrow cells, blood cells (e.g., lymphocytes), adipocytes, muscle cells, endothelial cells, etc. The cells are genetically engineered in vitro using recombinant DNA techniques to introduce the nucleic acid molecules of the invention into the cells.

Preferably, the agonistic binding molecules are secreted from the cells. The engineered cells which express and preferably secrete the binding molecules as described herein can be introduced into the patient for example systemically, e.g., in the circulation, or intraperitoneally. In other embodiments, the cells can be incorporated into a matrix or can be encapsulated and implanted in the body.

In another embodiment, activated CD4+ T-cells are removed from a patient and contacted with the agonistic binding molecules of the invention in vitro. Thereafter, the treated activated CD4+ T-cells are administered to the patient. In yet a further specific embodiment, the agonistic binding molecules of the invention and antigen-presenting cells are contacted with T-cells to stimulate T-cell proliferation in vitro.

In a specific embodiment, neoplastic, viral or bacterial antigens or combinations thereof can be administered before, concomitant or after administration of the agonistic binding molecules of the invention. Preferably, the antigens are administered to a subject with an neoplastic or infectious disorder or disease prior to (e.g., 2 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 2 days, 3 days, 4 days, 5 days, 7 days, 2 weeks, 4 weeks or 6 weeks before) the administration of the agonistic binding molecules of the invention. The antigens include, but are not limited to, recombinantly produced antigens, purified antigens, compositions comprising the antigens, neoplastic cells comprising the antigens, portions of neoplastic cells, such as for instance membranes, comprising the antigens, fragments of the antigens, viruses, bacteria, fungi, yeast and other microorganisms. If cells are used, the cells can be used directly after removal from the patient, but preferably the cells are first attenuated before administration to a patient. If viruses or bacteria or other infectious organisms are used, the organisms are preferably first attenuated before administration to a patient. Methods for attenuation are known in the art and include, but are not limited to, irradiation, heat treatment and chemical inactivation.

In connection with the treatment of neoplastic disorders or diseases, the agonistic binding molecules of the present invention may be used in combination with classical approaches, such as surgery, radiotherapy, chemotherapy, and the like. The human agonistic binding molecules and chemotherapeutic, radiotherapeutic or anti-angiogenic agents may be administered in a single composition or as two distinct compositions using identical or different administration routes. The invention therefore also provides combined therapies in which the agonistic binding molecules of the invention are used simultaneously with, before, or after surgery, radiotherapy or chemotherapy or are administered to patients with, before, or after conventional chemotherapeutic, radiotherapeutic or anti-angiogenic agents. When the administration of the human agonistic binding molecule precedes or follows the administration of the chemotherapeutic, radiotherapeutic or anti-angiogenic agents, intervals ranging from minutes to weeks may lie between the various administrations. It has to be ensured however that a significant period of time does not expire between the time of each delivery, such that the composition comprising the agent and the composition comprising the agonistic binding molecule will still be able to exert an advantageously combined effect on the neoplasm or tumor. In such instances, it is contemplated that one will contact the neoplasm or tumor with both compositions within about 2 minutes to about one week of each other and, more preferably, within about 12-72 hours of each other, with a delay time of only about 12-48 hours being most preferred.

In connection with the treatment of viral or bacterial disorders or diseases as mentioned above, the agonistic binding molecules of the present invention may be used in combination with anti-viral and/or anti-bacterial compounds as described above. An similar dosage regimen as indicated for the treatment of neoplastic disorders and diseases can also be applied for the viral or bacterial disorders or diseases, i.e. one or more human agonistic binding molecules or compositions comprising them may be administered to a subject with an infectious disease prior to (e.g., 2 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 2 days, 3 days, 4 days, 5 days, 7 days, 2 weeks, 4 weeks or 6 weeks before), concomitantly with, or subsequent to (e.g., 2 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 2 days, 3 days, 4 days, 5 days, 7 days, 2 weeks, 4 weeks or 6 weeks after) the administration of one or more anti-viral and/or anti-bacterial compounds.

Next to that, pharmaceutical packs or kits comprising at least one agonistic binding molecule, preferably human agonistic binding molecules such as human agonistic monoclonal antibodies according to the invention, at least one variant or fragment thereof, at least one immunoconjugate according to the invention, at least one nucleic acid molecule according to the invention, at least one composition according to the invention, at least one pharmaceutical composition according to the invention, at least one vector according to the invention, at least one host according to the invention or a combination thereof are also a part of the present invention. Optionally, the kits also contain other therapeutic or prophylactic compounds. Optionally, the above described components of the kits of the invention are packed in suitable containers and labeled for diagnosis, prophylaxis and/or treatment of the indicated conditions. The above-mentioned components may be stored in unit or multi-dose containers, for example, sealed ampules, vials, bottles, syringes, and test tubes, as an aqueous, preferably sterile, solution or as a lyophilized, preferably sterile, formulation for reconstitution. The containers may be formed from a variety of materials such as glass or plastic and may have a sterile access port (for example the container may be an intravenous solution bag or a vial having a stopper pierceable by a hypodermic injection needle). The kit may further comprise more containers comprising a pharmaceutically acceptable buffer, such as phosphate-buffered saline, Ringer's solution and dextrose solution. It may further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, syringes, culture medium for one or more of the suitable hosts. Associated with the kits can be instructions customarily included in commercial packages of therapeutic, prophylactic or diagnostic products, that contain information about for example the indications, usage, dosage, manufacture, administration, contraindications and/or warnings concerning the use of such therapeutic or diagnostic products. The documents providing instructions for the use of the agents of the kit can be in, e.g., written and/or electronic form.

EXAMPLES

To illustrate the invention, the following examples are provided. The examples are not intended to limit the scope of the invention in any way.

Example 1

Selection of Phage Carrying Single Chain Fv Fragments Specifically Recognizing Human OX40-Receptor Using OX40-Ig Fusion Protein.

Antibody fragments were selected using antibody phage display libraries and MAbstract™ technology, essentially as described in U.S. Pat. No. 6,265,150 and in WO 98/15833, both of which are incorporated herein in their entirety. All procedures were performed at room temperature unless stated otherwise. A human OX40-Ig fusion protein consisting of the extracellular domain of the human OX40-receptor linked to the CH2 and CH3 domains of human IgG1 was obtained commercially (Alexis Biochemicals) and coated for 2 hours at 37° C. onto the surface of Maxisorp™ plastic tubes (Nunc) at a concentration of 1.25 μg/ml. The tubes were blocked for 1 hour in 2% fat free milk powder dissolved in PBS (MPBS). Simultaneously, 500 μl (approximately 10¹³ cfu) of a phage display library expressing single chain Fv fragments (scFv's) essentially prepared as described by De Kruif et al. (1995a) and references therein (which are incorporated herein in their entirety), was added to two volumes of 4% MPBS. In addition, human serum was added to a final concentration of 15% and blocking was allowed to proceed for 30-60 minutes. The OX40-Ig-coated tubes were emptied and the blocked phage library was added. The tube was sealed and rotated slowly for 1 hour, followed by 2 hours of incubation without rotation. The tubes were emptied and washed 10 times in PBS containing 0.1% Tween-20, followed by washing 5 times in PBS. 1 ml glycine-HCL, 0.05 M, pH 2.2 was added, and the tube was rotated slowly for 10 minutes. The eluted phages were added to 500 μl 1M Tris-HCl pH 7.4. To this mixture, 3.5 ml of exponentially growing XL-1 blue bacterial culture was added. The tubes were incubated for 30 minutes at 37° C. without shaking. Then, the bacteria were plated on 2TY agar plates containing ampicillin, tetracycline and glucose. After overnight incubation of the plates at 37° C., the colonies were scraped from the plates and used to prepare an enriched phage library, essentially as described by De Kruif et al. (1995a). Briefly, scraped bacteria were used to inoculate 2TY medium containing ampicillin, tetracycline and glucose and grown at a temperature of 37° C. to an OD_(600nm) of ˜0.3. Helper phages were added and allowed to infect the bacteria after which the medium was changed to 2TY containing ampicillin, tetracycline and kanamycin. Incubation was continued overnight at 30° C. The next day, the bacteria were removed from the 2TY medium by centrifugation after which the phages were precipitated using polyethylene glycol 6000/NaCl. Finally, the phages were dissolved in a small volume of PBS containing 1% BSA, filter-sterilized and used for a next round of selection. The selection/re-infection procedure was performed twice. After the second round of selection, individual E. coli colonies were used to prepare monoclonal phage antibodies. Essentially, individual colonies were grown to log-phase and infected with helper phages after which phage antibody production was allowed to proceed overnight. Phage antibody containing supernatants were tested in ELISA for binding activity to human OX40-Ig coated 96 wells plates.

Example 2

Validation of the Human OX40R-Specific scFv's.

Selected phage antibodies that were obtained in the screen described above, were validated in ELISA for specificity. For this purpose, human OX40-Ig was coated to Maxisorp™ ELISA plates. After coating, the plates were blocked in 2% MPBS. The selected phage antibodies were incubated in an equal volume of 4% MPBS. The plates are emptied, washed once in PBS, after which the blocked phages were added. Incubation was allowed to proceed for 1 hour, the plates were washed in PBS containing 0.1% Tween-20 and bound phages were detected using an anti-M13 antibody conjugated to peroxidase. As a control, the procedure was performed simultaneously using a control phage antibody directed against thyroglobulin (De Kruif et al. 1995a and 1995b), which served as a negative control. As shown in FIG. 1, the selected phage antibodies called SC02008, SC02009, SC02010, SC02011, SC02012 and SC02021 displayed significant binding to the immobilized human OX40-Ig fusion protein.

The phage antibodies that bound to human OX40-Ig were subsequently tested for binding to human serum IgG to exclude the possibility that they recognized the Fc part of the fusion protein. None of the selected anti-OX40-receptor phages demonstrated binding to human IgG.

In another assay the phage antibodies were analyzed for their ability to bind PER.C6™ cells that recombinantly express human OX40-receptor. To this purpose PER.C6™ cells were transfected with a plasmid carrying a cDNA sequence encoding human OX40-receptor or with the empty vector and stable transfectants were selected using standard techniques known to a person skilled in the art (Coligan et al., 2001). For flow cytometry analysis, phage antibodies were first blocked in an equal volume of 4% MPBS for 15 minutes at 4° C. prior to the staining of the OX40-receptor- and control transfected PER.C6™ cells. The blocked phages were added to a mixture of unlabelled control transfected PER.C6™ cells and OX40-receptor transfected PER.C6™ cells that were labelled green using a lipophylic dye (PKH67, Sigma). The binding of the phage antibodies to the cells was visualized using a biotinylated anti-M13 antibody (Santa Cruz Biotechnology) followed by streptavidin-phycoerythrin (Caltag). As shown in FIG. 2, the selected anti-human OX40-receptor phage antibodies called SC02008, SC02009, SC02010, SC02011, SC02012 and SC02021 selectively stained the PER.C6™ OX40-receptor transfectant, while they did not bind the control transfectant.

In another assay the phage antibodies were analyzed for their ability to bind to OX40-receptor positive CD4+ T-cells derived from inflamed tonsils or from synovial fluid from patients suffering from rheumatoid arthritis. As a control, the staining pattern of the anti OX40-receptor phage antibodies on peripheral blood mononuclear cells (MNC) is also shown.

Inflamed tonsils were obtained from patients undergoing routine tonsillectomy. Tonsils were minced and the MNC fraction was isolated by density centrifugation. Flow cytometric analysis of the binding of the anti-OX40-receptor phage antibodies to the OX40+ CD4+ T-cells was performed as described above. The CD4+ T-cells were distinguished from total tonsil MNC using a FITC conjugated antibody against CD4. As shown in FIGS. 3A and 3B the selected anti-human OX40-receptor phage antibodies called SC02008, SC02009, SC02010, SC02011, SC02012 and SC02021 selectively stain a subset of CD4+ T-cells within tonsil and synovial fluid mononuclear cells respectively, while they display minor staining of peripheral blood CD4+ T-cells (FIG. 3C).

Example 3

Selection of Phage Carrying Single Chain Fv Fragments Specifically Recognizing Human OX40-Receptor Using OX40+ CD4+ T-Cells.

Phage selection experiments were performed as described supra, using lymphocytes as target. An aliquot of the phage library (500 μl, approximately 10¹³ cfu) were blocked with 2 ml RPMI/10% FCS/1% NHS for 15 minutes at room temperature. Tonsil MNC (˜10×10⁶ cells) were added to the blocked phage library and incubated for 2.5 hours while slowly rotating at 4° C. Subsequently, the cells were washed twice and were resuspended in 500 μl RPMI/10% FCS and incubated with a FITC-conjugated anti-CD4 antibody (Becton Dickinson) and a phycoerythrin-conjugated anti-OX40-receptor antibody (Becton Dickinson) for 15 minutes on ice. The cells were washed once and transferred to a 4 ml tube. Cell sorting was performed on a FACSvantage fluorescence-activated cell sorter (Becton Dickinson), and ˜15.000 CD4+ OX40+ cells were sorted. The sorted cells were spun down, the supernatant was saved and the bound phages were eluted from the cells by resuspending the cells in 500 μl 50 mM glycin pH 2.2 followed by incubation for 5 minutes at room temperature. The mixture was neutralized with 250 μl 1 M Tris-HCl pH 7.4 and added to the rescued supernatant. Collectively these phages were used to prepare an enriched phage library as described earlier. The selection/re-infection procedure was performed twice. After the second round of selection, monoclonal phage antibodies were prepared and tested for binding to tonsillar OX40+ CD4+ T-cells. Selected phage antibodies that met this criterium were subsequently tested for binding to OX40-receptor transfected PER.C6™ cells. The results in FIG. 4 show that the selected phage antibodies called SC02022 and SC02023 selectively bind to a subset of CD4+ T-cells within tonsil mononuclear cells (see FIG. 4A) and that they bind to the human OX40-receptor PER.C6™ transfectant (see FIG. 4B).

Example 4

Characterization of the Human OX40-Receptor Specific scFv's.

From the selected human OX40-receptor specific phage antibody (scFv) clones plasmid DNA was obtained and nucleotide sequences were determined according to standard techniques. Nucleotide sequences and amino acid translations of the scFv's called SC02008, SC02009, SC02010, SC02011, SC02012, SC02021, SC02022 and SC02023 are shown in FIGS. 5-12, respectively. The nucleotide sequences of the scFv's called SC02008, SC02009, SC02010, SC02011, SC02012, SC02021, SC02022 and SC02023 are also shown in SEQ ID NO:1, SEQ ID NO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13 and SEQ ID NO:15, respectively. The amino acid sequences of the scFv's called SC02008, SC02009, SC02010, SC02011, SC02012, SC02021, SC02022 and SC02023 are shown in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14 and SEQ ID NO:16, respectively. The VH and VL gene identity and heavy chain CDR3 compositions of the anti-human OX40-receptor scFv's are depicted in table 1.

Example 5

Production of Human OX40-Receptor Specific Bivalent scFv in Pichia Pastoris.

Methods for the cloning and expression of bivalent scFv fragments in the Pichia pastoris system were based on protocols provided by the supplyer (Invitrogen) in “A Manual of Methods for Expression of Recombinant Proteins Using pPICZ and pPICZa in Pichia pastoris (Version F)”. The bivalent scFv expression vector pPicZbiFVH (see FIG. 13B) was constructed from the vector pPICZαB (Invitrogen) (see FIG. 13A) following standard molecular biology techniques known to a person skilled in the art. Three modifications were introduced in the pPICZαB (see FIG. 13C):

-   -   1. A restriction site (NcoI) was introduced by PCR-generated         point mutation directly after the KEK2 cleavage site of the         signal peptide to facilitate cloning into the vector.     -   2. A second NcoI restriction site was removed by PCR generated         point mutation inside the coding region of the sh ble gene.     -   3. A synthetic fragment comprising the hinge region of murine         IgG3 and a linker fragment was introduced between the         restriction sites NotI and XbaI.

All modifications were confirmed by sequencing. ScFv's were cloned into pPicZbiFVH from the phage display expression vector by directional cloning using the restriction sites NcoI and NotI. The Pichia pastoris strain SMD1168 kek1:suc1 (ATCC #204414) was transformed with 5-10 μg of linearized construct cDNA by electroporation according to the manufacturer's protocols (supra). The transformed cells were plated on YPDS agar containing 250 μg/ml Zeocin and incubated at 30° C. for 3-4 days. High producing clones were selected by colony lift immunoblot screening, as follows. Pre-wet nitrocellulose membranes were layered over the transformation plates and a fraction of each colony was lifted onto the membrane. The membrane was then placed colony side up on YPD agar containing 0.5% methanol and incubated overnight at 30° C. The membranes were then washed repeatedly with Tris buffered saline containing 0.5% Tween-20 (TBST) to removed colonies, then blocked for 30 minutes with TBST and 4% non-fat milk powder. The membranes were then placed in TBST containing 4% non-fat milk powder and horseradish peroxidase conjugated anti-c-myc antibody (Roche) for 1 hour. Finally, the membranes were washed extensively in TBST followed by a PBS washing step and scFv-secreting colonies were revealed by a chemofluorescence detection system (Apbiochem). Selected high producers were purified by streaking on YPD plates and were subsequently used for bivalent scFv expression. Small-scale expression cultures were carried out in shaker flasks essentially as described by the manufacturer's protocols (supra). BMGY medium was used for the cell expansion phase, while BMMY medium was used during the bivalent scFv expression phase. After 48 hours of induction supernatants were clarified by repeated centrifugation. The supernatant was conditioned for purification by the addition of 1 M Na₂HPO₄ pH 8 to a concentration of 20 mM, 0.5 M Imidazole to a concentration of 10 mM, 5 M NaCl to a concentration of 500 mM. Hereafter, the samples were purified by immobilized metal affinity chromatography followed by anion exchange chromatography on an AKTAprime FPLC-system (Pharmacia). A 5 ml HiTrap™ chelating column (Pharmacia) was charged with NiSO₄ and equilibrated according to the manufacturers instructions. Conditioned supernatant was loaded directly on to the column and washed extensively in equilibration buffer (20 mM Na₂PO₄ pH 8, 10 mM imidazole). Bivalent scFv were eluted directly off the column on to a 1 ml sepharose Q HP column (Pharmacia) in the presence of 250 mM imidazole pH 8.5. The column was then washed in 20 mM Tris-HCl pH 8, then briefly in 20 mM Na₂PO₄ pH 7.3, and bivalent scFv's were eluted off the column over a gradient of 0-0.5 M NaCl in 7 column volumes. Fractions were then measured for protein content and were analyzed for activity and purity. The bivalent scFv clones of SC02008, SC02010, SC02011 and SC02023 were deposited at the European Collection of Cell Cultures (ECACC), CAMR, Salisbury, Wiltshire SP4 OJG, Great Britain on 15 May 2002, under accession numbers 02051563, 02051560, 02051561 and 02051562, respectively.

Example 6

Functional Analysis of Bivalent scFv Specifically Recognizing Human OX40-Receptor.

The anti human-OX40-receptor bivalent scFv's were validated for their ability to bind to OX40+ CD4+ T-cells within tonsil MNC. Tonsil MNC samples were obtained as described supra and were stained with the bivalent scFv's at a concentration of 5 μg/ml at 4° C. Binding of the bivalent scFv's was visualized using a biotinylated anti-myc antibody (9E10, Santa Cruz Biotechnology) followed by streptavidin-phycoerythrin (Caltag). The bivalent anti human-OX40-receptor scFv's displayed a similar staining pattern as the corresponding scFv's in phage antibody format.

The anti-human OX40-receptor bivalent scFv's were analyzed for their ability to interfere with OX40-receptor-mediated signaling in a costimulation assay. For this purpose 293T cells were transfected with either the empty vector or with an OX40-ligand cDNA-containing plasmid (pCDNA3.1zeo(+), In Vitrogen) using the lipofectamine reagent according to standard protocols. 48 hours after transfection, the cells were harvested, paraformaldehyde fixed and analyzed for cell surface expression of OX40-ligand by flow cytometry (OX40-ligand was visualized using the OX40-Ig fusion protein followed by incubation with a biotinylated goat-anti-human Fc polyclonal antibody (Caltag) and streptavidin-phycoerythrin (Caltag)). To cocultures of 1.5×10³ 293T transfectants and 4×10⁵ T-cells, which were activated with a submitogenic dose of 50 ng/ml of PHA (Abbot Murex), several concentrations of the bivalent anti-human-OX40-receptor or control scFv's were added. T-cells were purified via negative selection using the MACS system and a pan-T cell isolation kit (Myltenyi Biotec) from PBMC that were obtained from healthy donors by Ficoll-Hypaque density gradients. The cultures were performed in U-bottom 96 well plates for 5 days and the proliferation of the T-cells was measured by ³H-thymidine incorporation during the last 16 hours of culture. As shown in FIGS. 14A and 14B, the bivalent scFv's SC02008 and SC02023, respectively, display agonistic (stimulating) function in that they induce T-cell proliferation in a concentration dependent manner when incubated with the mock-transfected 293T cells. Interestingly, these agonistic bivalent anti human-OX40-receptor scFv's demonstrate a synergistic stimulatory effect when co-incubated with the OX40-ligand transfected 293T cells as compared to the level of proliferation that is reached with the same transfectant in the presence of a control bivalent scFv antibody.

Example 7

Construction of Fully Human Immunoglobulin Molecules from the Selected Anti-Human OX40-Receptor Single Chain Fv Fragments.

To use the selected antibody fragments that recognize human OX40-receptor for therapeutic applications in humans, it is desirable to generate human immunoglobulin molecules. The engineering and production of the human IgG1 monoclonal antibodies is essentially performed as described in detail by Boel et al. (2000). In detail, scFv were recloned in IgG expression vector C01 (pCRU-KO1). To that purpose, V_(H) and V_(L) regions were PCR amplified using designated primers to append restriction sites and restore complete human frameworks. The PCR fragments were cloned in pTOPO (Invitrogen), the integrity of the PCR-fragments was verified by sequencing and thereafter the inserts were sequentially cloned (EcoRI-BamHI for V_(H) and XhoI-NotI for V_(L)) into the IgG expression vector C01. ScFv 5′V_(H) oligo 3′V_(H) oligo 5′V_(L) oligo 3′V_(L) oligo 02-008 5H-B 3H-B 5K-E 3K-E 02-011 5H-B 3H-B 5K-E 3K-E 02-021 5H-B 3H-B 5K-G 3K-B 02-023 5H-B 3H-B 5K-H 3K-F

primer sequences: 5H-B: acctgtcttgaattctccatggccgaggtgcagctggtggagtctg (SEQ ID NO: 47) 3H-B: gctcgcggatccactcacctgaggagacggtcaccagggtgccctggcccc (SEQ ID NO: 48) 5K-E: acctgtctcgagttttccatggctgacatcgtgatgacacagtctccag (SEQ ID NO: 49) 5K-G: acctgtctcgagttttccatggctgacatcgtgatgacccagtctcc (SEQ ID NO: 50) 5K-H: acctgtctcgagttttccatggctgaaattgtgctcacacagtctccagccacc (SEQ ID NO: 51) 3K-E: ttttccttagcggccgcaaagtgcacttacgtttgatttccagtttggtgccctg (SEQ ID NO: 52) 3K-B: ttttccttagcggccgcaaagtgcacttacgtttgatttccactttggtgccctg (SEQ ID NO: 53) 3K-F: ttttccttagcggccgcaaagtgcacttacgtttgatctccaccttggtccctcc (SEQ ID NO: 54)

The resulting expression constructs pgG102-008C01, pgG102-011C01, pgG102-021C01 and pgG102-023C01 encoding the human IgG1 antibodies directed against human-OX40 receptor were transiently expressed in PER.C6™ cells and supernatants containing IgG1 antibodies were obtained. The expression constructs pgG102-008C01, pgG102-011C01, pgG102-021C01 and pgG102-023C01 were deposited at the European Collection of Cell Cultures (ECACC), CAMR, Salisbury, Wiltshire SP4 OJG, Great Britain on 9 Jun. 2003, under provisional accession numbers 03060601, 03060602, 03060603 and 03060604, respectively.

The nucleotide sequences of the heavy chains of the antibodies called 008, 011, 021 and 023 are shown in SEQ ID NOS:39-42, respectively. The amino acid sequences of the heavy chains of the antibodies called 008, 011, 021 and 023 are shown in SEQ ID NOS:25-28, respectively. The nucleotide sequences of the light chains of the antibodies called 008, 011, 021 and 023 are shown in SEQ ID NOS:43-46, respectively. The amino acid sequences of the light chains of the antibodies called 008, 011, 021 and 023 are shown in SEQ ID NOS:29-32, respectively. Subsequently, the antibodies were purified over size-exclusion columns and protein A columns using standard purification methods used generally for immunoglobulins (see for instance WO 00/63403).

The anti-OX40 receptor IgG1 antibodies were validated for their ability to bind to PER.C6™ cells transfected with human OX40-receptor. To this purpose mock- and human OX40-receptor-transfected cells were stained with the IgG1 antibodies at a concentration of 20 μg/ml at 4° C. Binding of the antibodies called 008, 011, 021 and 023 was visualized using biotinylated goat-anti-human IgG (Fc specific, Caltag) followed by streptavidin-phyco-erythrin (Caltag). The stained cells were analyzed by flow cytometry. All antibodies specifically recognized the human OX40-receptor on OX40-receptor-transfected PER.C6™ cells (filled histograms in FIG. 15,) while they did not bind the mock-transfected cell line (open histograms in FIG. 15).

Example 8

Functional Analysis of Fully Human IgG Molecules Specifically Recognizing Human OX40-Receptor.

The anti-OX40-receptor IgG1 molecules are validated for their ability to interfere with OX40R-mediated signaling in a costimulation assay as described supra. It is to be expected that at least one of the IgG1 molecules stimulates T-cell proliferation.

Example 9

Immunohistochemistry

The anti-OX40-receptor IgG molecules are biotinylated and subsequently analyzed for their ability to bind to OX40+ cells in inflamed tonsil and tumor sections with infiltrating lymphocytes by immunohistochemistry. Furthermore, they are analyzed for their ability to bind to normal tissues. To this purpose, frozen sections of the following normal tissues: adrenal gland; bladder; brain (cerebellum and cerebrum); blood vessels (aorta and coronary artery); fallopian tube; oesophagus; stomach (antrum and body); duodenum; ileum; colon; heart; kidney; liver; lung; lymphnode; ovary; pancreas; parathyroid; peripheral nerve; pituitary gland; placenta; prostate; salivary gland; skin; spinal cord; spleen; striated muscle; testis; tonsil; thyroid; ureter and uterus (cervix and endometrium) as well as inflamed tissues and tumor tissues are cut, mounted on glass slides and are dried at room temperature. The sections are blocked for endogenous peroxidase with 50 mM sodium azide containing 0.03% H₂0₂ for 20 minutes, followed by blocking for endogenous biotin according to the provided protocol (X0590, Dako). Subsequently, the sections are blocked with PBS containing 4% BSA and 10% normal human serum prior to incubation with the biotinylated anti-human OX40 receptor IgG's for 60 minutes at room temperature. To detect bound IgG molecules the sections are incubated with streptavidin coupled-horseradish peroxidase (Dako) followed by incubation with diaminobenzidine (Sigma) resulting in a local deposition of brown crystals. The sections are counterstained with hematoxilin to visualize nucleated cells within the sections. Prior to analysis the sections are dehydrated and the slides are sealed with eukitt (BDH).

Example 10

In vivo Analysis of Enhanced Immune Response Induced by Agonistic Anti-Human OX40-Receptor Binding Molecules.

To determine the cross-reactivity of the anti-human OX40-receptor antibodies with mouse OX40-receptor, splenic OX40+ CD4+ T-cells are analyzed by flow cytometry. Murine OX40+ T-cells are generated by stimulating C57B16 splenic CD4 T-cells that are isolated using an anti-CD4-phycoerythrin antibody (Pharmingen) and anti-phycoerythrin labeled MACS beads (Myltenyi Biotec) with a mitogenic dose of PHA and IL2. The cells are analyzed after 72 hours of stimulation with a rat antibody against the murine OX40-receptor and with the panel of anti-human OX40-receptor antibodies (supra). In case the agonistic anti-human OX40-receptor antibodies display cross reactivity with mouse OX40-receptor, the OX40-receptor can be engaged in vivo with these agonistic antibodies to demonstrate the delivery of a costimulatory signal to effector T-cells. To demonstrate the effect of providing an agonistic anti-OX40-receptor antibody to T-cells during tumor priming in vivo, a MCA 303 sarcoma tumor model in C57BL/6 mice is used as described by Weinberg et al. (2000) and in WO 99/42585. Mice are inoculated subcutaneously at day 0 with 1−3×10⁵ MCA 303 sarcoma tumor cells. Three days later the animals are given intraperitoneal injections with the agonistic anti-human OX40-receptor antibodies at doses ranging from 100-500 μg per animal. A second dose is given 7 days after tumor inoculation. The animals are then monitored for tumor growth for over 50 days, animals are sacrificed when tumor sizes exceed 1 cubic cm. When animals that are given the agonistic anti-human OX40-receptor antibodies remain tumor free (or have tumours smaller in size than control animals), while animals that are given the tumor cells alone have to be sacrificed, this indicates that engagement of the OX40-receptor by the agonistic anti-human OX40-receptor antibodies costimulate effector T-cells to exert their tumor eradicating function. Alternatively, the experiment described above can also be performed in a transgenic mouse model in which human OX40-receptor is expressed under a T-cell specific promoter. Such a mouse can be created according to protocols known to the person skilled in the art of transgenic mouse models. TABLE 1 SEQ ID SEQ ID NO of NO of nucle- amino otide acid V_(H)- V_(L)- Name se- se- germ- germ- scFv quence quence CDR3 line line SC02-008 SEQ ID SEQ ID DRYSQVHYAL V_(H)3 V_(K)II NO: 1 NO: 2 DY DP47 (SEQ ID NO: 17) SC02-009 SEQ ID SEQ ID DRYVNTSNAF V_(H)3 V_(K)II NO: 3 NO: 4 DY DP29 (SEQ ID NO: 18) SC02-010 SEQ ID SEQ ID DMSGFHEFDY V_(H)3 V_(K)I NO: 5 NO: 6 (SEQ ID NO: 19) DP49 SC02-011 SEQ ID SEQ ID DRYFRQQNAF V_(H)3 V_(K)II NO: 7 NO: 8 DY DP47 (SEQ ID NO: 20) SC02-012 SEQ ID SEQ ID ARAAGTIFDY V_(H)3 V_(K)II NO: 9 NO: 10 (SEQ ID NO: 21) DP29 SC02-021 SEQ ID SEQ ID DRYITLPNALD V_(H)3 V_(K)II NO: 11 NO: 12 Y DP50 (SEQ ID NO: 22) SC02-022 SEQ ID SEQ ID YDEPLTIYWFD V_(H)3 V_(K)III NO: 13 NO: 14 S DP44 (SEQ ID NO: 23) SC02-023 SEQ ID SEQ ID YDNVMGLYWF V_(H)3 V_(K)II NO: 15 NO: 16 DY DP52 (SEQ ID NO: 24)

REFERENCES

-   Al-Shamkhani, A., Birkeland, M. L., Puklavec, M., Brown, M. H.,     James, W., and Barclay, A. N. (1996) OX40 is differentially     expressed on activated rat and mouse T cells and is the sole     receptor for the OX40 ligand. Eur J Immunol 26:1695-1699. -   Boel E, Verlaan S, Poppelier M J, Westerdaal N A, Van Strijp J A and     Logtenberg T (2000) Functional human monoclonal antibodies of all     isotypes constructed from phage display library-derived single-chain     Fv antibody fragments. J Immunol Methods 239:153-166. -   Burton D R and Barbas C F (1994) Human antibodies from combinatorial     libraries. Adv Immunol 57:191-280. -   Coligan J E, Dunn B M, Ploegh H L, Speicher D W and Wingfield P T     (eds.) (2001) Current protocols in protein science, volume I. John     Wiley & Sons, Inc., New York. -   De Kruif J, Terstappen L, Boel E and Logtenberg T (1995a) Rapid     selection of cell subpopulation-specific human monoclonal antibodies     from a synthetic phage antibody library. Proc Natl Acad Sci USA     92:3938. -   De Kruif J, Boel E and Logtenberg T (1995b) Selection and     application of human single chain Fv antibody fragments from a     semi-synthetic phage antibody display library with designed CDR3     regions. J Mol Biol 248:97. -   Huls G, Heijnen I J, Cuomo E, van der Linden J, Boel E, van de     Winkel J and Logtenberg T (1999) Antitumor immune effector     mechanisms recruited by phage display-derived fully human IgG1 and     IgA1 monoclonal antibodies. Cancer Res 59: 5778-5784. -   Kaleeba, J. A., Offner, H., Vandenbark, A. A., Lublinski, A., and     Weinberg, A. D. (1998) The OX-40 receptor provides a potent     co-stimulatory signal capable of inducing encephalitogenicity in     myelin-specific CD4+ T cells. Int Immunol 10:453-461. -   Kohler G and Milstein C (1975) Continuous cultures of fused cells     secreting antibody of predefined specificity. Nature 256:495-497. -   Lekkerkerker A and Logtenberg T (1999) Phage antibodies against     human dendritic cell populations obtained by flow cytometry-based     selection on freshly isolated cells. J Immunol Methods 231:53-63. -   Sambrook and Russell (2001) Molecular Cloning, a Laboratory Manual,     third edition. Cold Spring Harbor Laboratory Press, Cold Spring     Harbor, N.Y. -   Van Kroonenburgh, M. J., and Pauwels, E. K. (1988) Human     immunological response to mouse monoclonal antibodies in the     treatment or diagnosis of malignant diseases. Nucl Med Commun     9:919-930. -   Weinberg, A. D., Rivera, M. M., Prell, R., Morris, A., Ramstad, T.,     Vetto, J. T., Urba, W. J., Alvord, G., Bunce, C., and     Shields, J. (2000) Engagement of the OX-40 receptor in vivo enhances     antitumor immunity. J Immunol 164:2160-2169. 

1. A human binding molecule comprising an agonistic binding molecule capable of binding to and stimulating the human OX40-receptor.
 2. The human binding molecule of claim 1, wherein the binding molecule has a synergistic stimulatory effect when co-incubated with OX40-ligand.
 3. The human binding molecule of claim 46, wherein the binding molecule comprises at least a complementary determining region comprising the amino acid sequence selected from the group consisting of SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23 and SEQ ID NO:24.
 4. The human binding molecule of claim 46, wherein the binding molecule comprises a heavy chain comprising an amino acid sequence selected from the group consisting of SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27 and SEQ ID NO:28.
 5. The human binding molecule of claim 46, comprising a functional variant of a binding molecule comprising at least one amino acid sequence selected from the group consisting of SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, and SEQ ID NO:28, wherein the functional variant is capable of specifically binding to the human OX40-receptor.
 6. The human binding molecule of claim 46, wherein the binding molecule comprises an immunoconjugate comprising at least one tag.
 7. A nucleic acid sequence encoding the human binding molecule claim
 46. 8. A vector comprising at least one nucleic acid sequence of claim
 7. 9. A host comprising at least one vector according to claim
 8. 10. The host of claim 9, wherein the host is a human cell.
 11. A method of producing a binding molecule capable of binding to and stimulating the human OX40-receptor, the method comprising: culturing a host comprising at least one vector encoding a binding molecule or functional variant thereof capable of binding to and stimulating the human OX40-receptor under conditions conducive to the expression of the binding molecule or functional variant; depressing the binding molecule or functional variant; and isolating the binding molecule or functional variant.
 12. The binding molecule or functional variant thereof, produced by the method according to claim
 11. 13. A method of identifying a binding molecule capable of specifically binding to the human OX40-receptor or a nucleic acid molecule encoding a binding molecule specifically binding to the human OX40-receptor, the method comprising: contacting a phage library of binding molecules with the extracellular domain of the human OX40-receptor, selecting at least once for phage binding to the human OX40-receptor, and separating and recovering the phage binding to the human OX40-receptor.
 14. The method according to claim 13, further comprising isolating from the recovered phage the binding molecule or the nucleic acid molecule encoding the binding molecule.
 15. A composition comprising the human binding molecule 46 and a stabilizing molecule.
 16. A composition comprising the nucleic acid molecule of claim 7 and a gene delivery vehicle.
 17. A pharmaceutical composition comprising the human binding molecule claim 46 and at least one pharmaceutically acceptable excipient.
 18. The pharmaceutical composition of claim 17 further comprising at least one other therapeutic agent. 19-26. (canceled)
 27. A method for modulating a T-cell response in a subject, said method comprising administering to said subject an effective dose of a composition comprising the binding molecule of claim 1 in an amount sufficient to bind to and stimulate the OX40-receptor in the subject.
 28. The method of claim 27, wherein said modulation comprises stimulation of T-cell proliferation.
 29. The method according to claim 27, wherein the subject is a human.
 30. The method according to claim 11, said method further comprising recovering the expressed binding molecule or functional variant.
 31. The method according to claim 27, wherein the binding molecule comprises a complementary determining region comprising an oligopeptide sequence consisting of 10 to 12 amino acids, wherein the oligopeptide sequence is Xaa₁-Xaa₂-R-Xaa₃-Asp-Xaa₄, wherein Xaa₁ is selected from the group consisting of Ala, Tyr, and Asp, Xaa₂ is selected from the group consisting of Asp, Arg and Met, R is selected from the group consisting of a pentapeptide or a heptapeptide, Xaa₃ is Phe or Leu, and Xaa₄ is Tyr or Ser, wherein the binding molecule binds to and stimulates the OX40-receptor in the subject.
 32. The method according to claim 31, wherein the complementary determining region is selected from the group consisting of SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23 and SEQ ID NO:24.
 33. The method according to claim 31, wherein the binding molecule comprises a sequence selected from the group consisting of SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27 and SEQ ID NO:28.
 34. The method according to claim 31, wherein the binding molecule further comprises at least one tag that enhances an immune response in the subject.
 35. The method according to claim 31, wherein administering to said subject an effective dose of the binding molecule further comprises administering to said subject an effective dose of a nucleic acid sequence encoding the binding molecule, wherein the nucleic acid sequence is operably linked to a regulatory sequence, and expressing the binding molecule in the subject.
 36. The method according to claim 27, wherein the composition further comprises at least one pharmaceutically acceptable excipient.
 37. The method according to claim 27, comprising enhancing an immune response in the subject.
 38. The method according to claim 37, comprising enhancing the immune response against a tumor, bacteria or viral antigen.
 39. A method of treating neoplastic, viral or bacterial diseases, the method comprising: administering the binding molecule of claim 1 to a subject believed to be in need thereof.
 40. A method for modulating a T-cell response in a subject, comprising: administering an effective dose of a binding molecule to a subject, wherein the binding molecule comprises a complementary determining region comprising an oligopeptide sequence consisting of 10 to 12 amino acids, wherein the oligopeptide sequence is Xaa₁-Xaa₂-R-Xaa₃-Asp-Xaa₄, wherein Xaa₁ is selected from the group consisting of Ala, Tyr, and Asp, Xaa₂ is selected from the group consisting of Asp, Arg and Met, R is selected from the group consisting of a pentapeptide or a heptapeptide, Xaa₃ is Phe or Leu, and Xaa₄ is Tyr or Ser; binding the binding molecule to an OX40-receptor in the subject; enhancing an immune response in the subject; and stimulating the OX40-receptor, thereby modulating the T-cell response in the subject.
 41. The method according to claim 40, wherein the binding molecule comprises at least one amino acid sequence selected from the group consisting of SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, and SEQ ID NO:28.
 42. The method according to claim 41, wherein the binding molecule comprises SEQ ID NO:25 and SEQ ID NO:29.
 43. The method according to claim 41, wherein the binding molecule comprises SEQ ID NO:26 and SEQ ID NO:30.
 44. The method according to claim 41, wherein the binding molecule comprises SEQ ID NO:27 and SEQ ID NO:31.
 45. The method according to claim 41, wherein the binding molecule comprises SEQ ID NO:28 and SEQ ID NO:32.
 46. The human binding molecule of claim 1, wherein the binding molecule comprises a complementary determining region comprising an oligopeptide sequence consisting of 10 to 12 amino acids, wherein the oligopeptide sequence is Xaa₁-Xaa₂-R-Xaa₃-Asp-Xaa₄, wherein Xaa₁ is selected from the group consisting of Ala, Tyr, and Asp, Xaa₂ is selected from the group consisting of Asp, Arg and Met, R is selected from the group consisting of a pentapeptide or a heptapeptide, Xaa₃ is Phe or Leu, and Xaa₄ is Tyr or Ser.
 47. The nucleic acid of claim 7, wherein said nucleic acid molecule encodes a binding molecule having an amino acid sequence selected from the group consisting of SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28.
 48. The human binding molecule of claim 5, comprising SEQ ID NO:25 and SEQ ID NO:29.
 49. The human binding molecule of claim 5, comprising SEQ ID NO:26 and SEQ ID NO:30.
 50. The human binding molecule of claim 5, comprising SEQ ID NO:27 and SEQ ID NO:31.
 51. The human binding molecule of claim 5, comprising SEQ ID NO:28 and SEQ ID NO:32. 